the main / the Internet / Deleted the boot sector of the disk what to do. New BIOS parameter block

Removed the boot sector of the disk what to do. New BIOS parameter block

Very often the cause of the computer failure is damage to the boot sector or the main boot record.

It fails to start the computer in safe mode, or in the last successful configuration mode. The computer may not produce errors, or on the screen you will see the following entries:

NTLDR Is Missing. Press Ctrl + Alt + Del to Restart,

Unable to run Windows due to a spoiled or missing file: \\ Windows \\ System32 \\ Config \\ System

How to restore the boot sector and boot record using the recovery console?

For Windows XP:

To do this, in BIOS, select the download from the CD / DVD disk or set the boot priority from the CD / DVD disk. File download starts. After the download is completed, click R - run the recovery console.

Which copy of Windows do you need to log in?

1: C: \\ Windows What copy of Windows should I log in? Enter 1, press ENTER.

A message will appear:

** Warning ** There is a non-standard or invalid main boot record on this computer. When using FixMBR, you can damage the existing partition table. This will lead to the loss of access to all sections of the current hard disk. If there are no problems of access to the disk, it is recommended to interrupt the operation of the FixMBr command. Confirm the recording of the new MBR?

Click: Y.

The new basic boot record is recorded. Wait for the corresponding message.

Enter the FixBoot command.

A message will appear: the end section: C:. Want to record a new boot sector in section C :?

Press the Y button.

A message will appear: File system in the boot section: NTFS (or FAT32). FixBoot command writes a new boot sector. The new boot sector has been successfully recorded.

We recruit an exit to exit the console. Now, if the problem was really in this, the computer will turn on without problems.

For Windows 7.

For Windows 7, the commands are few others. Yes, and the console will also start differently.

How to recover Windows 7 bootloader?

You also need a disk with the operating system WINOWS 7. Loading from the disk, as in the case of Windows XP.

After downloading the main files, the Language Parameter Selection window will appear. Downstairs there will be a button restore system.

Press it and choose need option. In our case, the command line.

Also recruit the following commands. First

bootRec / FixBoot (or bootrec.exe / fixboot)

bootRec / FixMBr (or bootrec.exe / fixboot)

Also press the exit to exit the console.

In the case of Windows 7, the recovery console can be launched without a disk using the recovery tools at startup. As a rule, the system itself will offer you to start the recovery tool in case of failure.

Note: If suddenly you see that the letter system Disc In the recovery console differs from your (that is, you know exactly what the OS was installed on the disk D, and not on C, simply enter the letter of the disc in the console. For example: D :)

We hope that you can restore the work of the OS. However, this method will not necessarily help you. Be careful. The site authors are not responsible for the possible harm caused to your PC.

But with her there are problems. When a computer running this OS refuses to load, it may be necessary to restore the HDD boot sector from which the entire system is initialized and starting.

If the problem is not related to user actions, as a rule, built-in windows diagnostics 7 will independently solve the problem, it is enough to wait for the reboot after an unsuccessful start, in which you will be offered to boot into the system recovery tool and choose the option of self-correcting.

So, if you faced the problems described at the beginning of this material, the first thing calm down, nothing terrible happened and everything can be corrected, since the restoration of the boot sector for the modern operating system is the procedure regular.

Your actions will differ depending on what exactly led to the inability to boot into the "seven".

If you installed over Win7 WinXP operating system - it means you should download EasyBCD program. Running it in XP you can in several simple action restore the bootloader and return to the list windows downloads 7.

If you, for example, installed Windows XP on top of Windows 7 and booted through EasyBCD, and then, for some reason, we decided to demolish the section from XP to the HDD - it means you have a more complex situation. Dive XP, you deleted and easybcd, which means that now the computer does not know how to download at least some OS.

To restore the boot sector of Windows 7 will have to remember where you have a Win7 recovery disk (you certainly created it, however?) Or, if the answer is negative, then we do not care what you find that you are, then insert into the drive . Now you need to boot from the disk, and enter the section "Restore System". Using the bootrec.exe utility, which is available on installation disk And the recovery disk "Seven" restore the boot sector Win7 will not take much time.

When you select "Restoring System", you will soon have options after a short wait, most likely will be able to restore only one OS - Windows 7. On the next screen below, you will see the "Command String" option, click on it and the window opens, which will need to dial several commands.

First, check whether everything is in order with the BootRec utility, for this enter in bootrec and press the Enter key. Next, each command must be completed by pressing this key. There will be text describing the capabilities of the utility.

In order to start recovering the boot sector, you score the command

If in response the computer will write that the "operation is successful" means everything is in order and the loader overwritten. You can go to the second part, type the command

bootRec / FixBoot

After you press the input, the computer will form a new boot sector, everyone can now dial the command.

After all these manipulations, you can enjoy the normal operation of your OS.

As you were convinced, the restoration of the Windows 7 boot sector is a really simple procedure.

Load from the emergency system diskette and run the SYS C: which will create on the system disk Boot Sector and copies the system files there. Make sure that the versions of operating systems on a diskette and on the recoverable disk coincide.

BOOT SECTOR recovery is easier to perform "automatic" method, but this does not exclude the possibility of "manual" recovery with a pencil, paper and disk editor. As mentioned above, if there are intact (or at least partially damaged) elements of the logical structure, save them as files on the backup disk.

Not an easy case. Destroyed not only boot sector

But there is a copy of the necessary system regions in the form of files or disk areas.

Follow the standard formatting of the main disk partition, i.e. team Format C: In this case, the file structure of the formatted disc partition is formed with the recreation of Boot Sector, clean FAT and ROOT Directory, the data area is not affected, i.e. Information in Data Area does not change.

Check the location of the root directory. For this diskeditor-Oh, in the recording cluster mode of the newly created partition, by specifying the search for the "subdirectory" object, check the coincidence of the physical cluster numbers and the cluster number in the first record of the subdirectories found. In case of incomprehension of numbers, you must correct the value of the number of FAT sectors in the boot sector boot record. Adjustment is carried out by increasing sectors by the number of multiple half of the number of sectors in the cluster. As a rule, such an adjustment is necessary in cases of non-standard disk breaking or after changes in the size of the sections with artificial means.

If you are lucky, and you have reserved in the form of files surviving FAT and / or Root Directory, using the diskeditor-Ohm restore them on the disk. If you survived the second copy of the FAT, and the first is not, you should copy the second copy and the first copy place.

If you have survived one of the copies of the FAT and the root directory, after executing all items above the above items, full access to information on the disk will be restored.

How to restore boot sector manually

The boot sector address can be found in the physical sector with the coordinates of 0/0/1 (Track / Head / Sector) in the appropriate partition Table element. Next, you need to go to this sector and view it in the Boot Record format (F7 key in program disk Editor). If in the root sector fields is "trash", then you need to manually restore this sector. You need to score with zeros the rest of the boot sector or copy to this place the boot sector of the system diskette if the disc partition is active (C :) Then you need to manually fill in the control fields of this sector:

Boot Record field	Correct value
	You can record your name here.
Bytes per sector
Sectors Per Cluster.	Calculate later
Reserved sectors at beginning

Root Directory Entries.
Total Sectors on Disk	This value is taken from the PARTITION TABLE (field + 0CH in the corresponding element)
Media Descriptor Byte
SECTORS PER FAT.	Calculate later
Sectors Per Track
	The value is taken from DRIVE INFO
Special hidden sectors	This value is equal to the Relative Sectors value (the relative number of the elementary sector) (field + 08h in the corresponding partition table) if the disk is not bootable, then the number 8388608 (800000h) is added to this value.

This table remained empty sectors per FAT fields and Sectors Per Claster (sectors on the cluster). They must be calculated additionally:

SECTORS PER FAT. : We view the disk sectors following Boot Record until we find the start of the indigenous catalog. We remember the coordinates of the catalog sector. Then we calculate the relative number of this sector relative to the Boot Record based on the number of parties on the disk, the number of sectors on the track and the relative address Boot Record \u003d 1. Then we find the S / F field:

S / F: \u003d (<Относ. сектор каталога> -1) Div 2.

SECTORS PER CLASTER. : This value must be chosen from the calculation that it can take 8 SECT / CLAST or 4 SECT / CLAST values.

Note. The following description refers to FAT 16. If FAT 32 is used on the disk, refer to it description

What to do when the disk section on the server or workstation becomes inaccessible?

Symptoms

When the disc partition on the server or the workstation becomes inaccessible or Disk Administrator defines it as an "unknown" (unknown), the reason may be convened in a damaged or damaged boot sector. This article will help you restore the boot sector using the second copy of it that NTFS saves.

Keep in mind that for the application of the tips described in the article, two conditions must be performed:

1. The file system of the damaged partition of the NTFS disk. Fat does not save a copy of the boot sector now.

2. Ability to download a computer in Windows NT or 2000 or XP.

Note: If you can't boot under one of the specified operating systems, Connect the hard drive to another computer on which it is possible.

Solution to the problem

To solve the problem, you need to get an archive copy of the boot sector and copy it to a specific part of the hard disk.

In NT 3.5x, the second copy is stored in the center of the logical disk.

In NT 4.0 and Windows 2000, it is transferred to the end of the logical disk, which requires other equipment for recovery. The example described will use special utility Disk Probe (dskprobe.exe) for NT, which comes with NT V4.0 Resource Kit. It can be rewritten and as part of the SP2 support package for Windows XP on this page. Disk Probe works and under NT v3.5x.

Note: To be able to restore in case of error when conducting the following procedures, while viewing the boot sectors that will be changed, just in case, save their copies into files (Save AS command from the File menu).

Restoring the boot sector of the main partition of the disk

1. In Disk Probe, select Drives, Physical Drive, select PhysicalDrivex, where X is the disk number. To determine the disk number, use the DISK Administrator utility. For example, if three SCSI discs are installed in the system, with SCSI ID numbers 1.3 and 5, Disk Administrator will show their numbers 0, 1, 2. After disconnecting the SCSI ID 3, its place will take the following (5). In the Disk Administrator numbering it will be 1.

2. Two times click on the PhysicalDrivex you want to restore. In the field, take the Read ONLY option in the field and press the SET ACTIVE button. You will notice that Active Handle was installed in PhysicalDrivex, click OK.

3. From the Sectors menu, select Read and specify 0 for Starting Sectors and 1 for Number of Sectors. Click Read. After that you will find yourself about the main boot record of the physical disk (MBR). In this, you can verify the ASCII text on the right side of the window, starting with an 8B offset, which should display "Invalid Partition Table". From the View menu, select Partition Table. In the area called "Partition Table Index" using the scrolling band, select the section in question and click it twice. On the left below shows the relative number of the Relative Sector sector, write this value and select the GO tab for this area.

4. Now from the View menu, select Bytes. Depending on how the boot sector is damaged, you can even consider some lines of text on the upper right side of the window or see the read error message "A disk Read. Error Ocurred ... ", starting with an offset 130. From the View menu, select" NTFS BootSector ".

5. Select "VOLUME END" for NT V4.0 or "Volume Middle" for NT v3.5x. Now you must be on an archive copy of the boot sector. If you see the message "Incomplete Data Read" or, after viewing, determine that this is not a copy of the boot sector, it may mean that your main sector was damaged, so we got the wrong address of the archive copy address. In this case, go to the next section of our article to learn how to restore the boot sector if it is missing or badly damaged. If everything is fine, go to the next item.

6. From the View menu, select Bytes and check that it is bootable nTFS sector. When we were convinced of this, select Write in the Sectors menu. Make sure that the correct values \u200b\u200bof Handle and PhysicalDrive are displayed in the dialog box. In the Starting Cecjtor to Write Data field, specify the relative sector number (Relative Sector) recorded by you in paragraph 4. Press the WRITE button.

7. In the Sectors menu, specify the relative sector number (Relative Sector), leaving the number of sectors (Number of Sectors) in the field (Number of Sectors), select Read. Now make sure that the data was recorded successfully.

Restoring a copy of the boot sector if there is no original copy, or it is badly damaged

If the boot sector is not or damaged to so much that it does not have correct information about the number of sectors, restoration can be carried out according to this plan:

1. In Disk Probe, select Drives, PHYSICAL DRIVE. Select PhysicalDrivex, where X is a disk number that can be found in Disk Administrator.

2 . Double pressing open the necessary PhysicalDrivex, in the bottom field, remove the READ ONLY mark and select SET ACTIVE. You should notice that Active Handle is set to PhysicalDrivex. Click OC.

5. Further we will need two values: Total Sectors (total sectors) and Relative Sectors (relative sector number). Record the value of Relative Sectors, it is here that the boot sector should be. To find it a copy, you will need to carry out uncomplicated calculations.

6. Select sectors. In the Starting Sector field, we enter a value defined in the previous step. In the Number of Sectors field, we enter 1. Click Read and we must get to the archive copy of the boot sector.

7. From the View menu, select Bytes and check whether this is the NTFS sector. After checking, go to the Sectors menu, select Write, and check the Handle and PhysicalDrive value in the dialog box that appears. In the "Starting Sector to Write Data" field, specify the relative sector number that you recorded (Relative Sectors) and click the Write button.

8. In the Sectors menu, specify the relative sector number, in the number of sectors (Number of Sectors), enter 1, select Read. Now you can make sure that the data was recorded correctly.

9. Close the Disk Probe and restart the computer.

Restoring the boot sectors of the extended disk partition

1 . In Disk Probe, select Drives, PHYSICAL DRIVE. Select PhysicalDrivex, where X is a disk number that can be found in Disk Administrator.

2. Double pressing open the necessary PhysicalDrivex, in the bottom field, remove the READ ONLY mark and select SET ACTIVE. You should notice that Active Handle is set to PhysicalDrivex. Click OC.

3. From the sectore menu, select Read. In the Starting Sector field (Starting Sector), set the value 0, and for the number of sectors (Number of Sectors) - 1. Press READ.

4. Now you are in the boot record (MBR) of the physical disk. This can be seen in the text that is displayed from the position 8B, which should look something like this: "Invalid Partition Table ...". From the View menu, select Partition Table. In this mode, in the Partition Table Index field, select the Extended Disc Area section. Next, in the System ID field, an extended value should appear. If the required section is the fourth logical disk In the extended area, the NEXT Partition button will have to be pressed four times. The System ID field must be NTFS.

5. In the Pattition Table Index region, click on the required section in the extended area of \u200b\u200bthe disk. System ID should appear Extended.

Go to the logical to the one you want to restore. If it is the second in this area of \u200b\u200bthe disk, the Next Partition button must be pressed twice. When transitions between the volumes of the extended disk partition in the System ID field will be displayed. file system Each volume.

When the section to be recovered is found, record the current sector number (Current Sector in the Disk Probe header), the relative sector number (Relative Sector) and the total number of sectors in this volume (Total Sectors). This information will be needed to calculate the location of the archive copy of the boot sector.

6. Press the GO button to go to the damaged volume to the boot sector. Record the number of this sector from the window title (Boot Sector).

To verify that you are on the right sector, select Bytes from the View menu. If the sector is badly damaged, you will see an error message in the right part.

To find a copy of the boot sector, we will need three recorded values: the current sector, the relative sector number and the total number of sectors.

7. We will make the necessary calculations:

8. Select Sectors, Read and enter the Starting Sector in the Starting Sector field. Number of sectors (Number of Sectors 1). Select Read and you should find yourself in the sector, where the archive copy of the boot sector is located.

From the View menu, select Bytes and make sure it is the NTFS boot sector. If this is not the case, an error message should appear in the right column of the text. In this case, do not continue, start the whole process first to exclude errors.

9. After you were convinced that they found an archive copy of the boot sector, write it down on top of the main one. In the sectors menu, select Write. In the dialog box that appears, check the values \u200b\u200bof handle and physicaldrive. In the Starting Sector field, enter the sector number in which the damaged boot sector is located. Click the "Write IT" button to record.

10. In the Sectors menu, select Read. As the elementary sector, specify the sector number to which you recorded an archive copy, the number of sectors again 1. Select Read and make sure that the data were recorded.

11. Close the Disk Probe and restart the computer.

application

The actions described are suitable for:

Microsoft Windows 2000 Server
Microsoft Windows 2000 Advanced Server
Microsoft Windows 2000 Professional Edition
Microsoft Windows NT Workstation 3.5
Microsoft Windows NT Workstation 3.51
Microsoft Windows NT Workstation 4.0 Developer Edition
Microsoft Windows NT Server 3.5
Microsoft Windows NT Server 3.51
Microsoft Windows NT Server 4.0 Standard Edition
Microsoft Windows XP.
Microsoft Windows XP SP2