TechTips - Repair Vista System Files with System File Checker

Vista comes with a great tool called System File Check (SFC) that checks all Vista System Files to make sure they are where they should be and are not corrupted, changed or damaged. The guide will detail how to check and repair any problems with the Vista System Files using the System File Checker and the command line.

1. First thing you will want to do is open an command prompt, to do this navigate to C:\Windows\System32\cmd.exe and then right click cmd.exe and choose run as an administrator.

2. At the command prompt you will want to type the command for the SFC that you want to use. There are many different commands and switches for you to choose from, choose from the ones listed below. I give a brief description of what each command does and what it will do.

3. sfc /verifyonly - Scans and verifies the integrity but doesn't make any changes to the files even if there is a problem. You can do this just to verify if your files are corrupted or to check if they are OK. (If it does find a problem you will want to run the sfc /scannow command so it will fix the problems for you.)

4. sfc /scannow - this will do a scan and verify the integrity of all system files and repairs the files if needed. (This command will restore Vista's original setup of system files. I prefer to run the sfc /verifyonly command first to check for problems. Then if it finds some I run this command)

6. sfc /verifyfile=(path of file) - Scans a chosen system file and verifies if it is corrupted or if it's ok. (Example: sfc /verifyfile=C:\windows\system32\bootstr.dll)

5. sfc /scanfile=(path of file) - Scans a chosen system file and repairs it if needed. (Example: sfc /scanfile=C:\windows\system32\bootstr.dll)

7. sfc /? - Used to display all of the sfc options with a brief description of each.

Typically I like to do the sfc /verifyonly first, this will just do a check on all of your system files but doesn't change anything. Once the scan is done you will know if you have any errors and if you need to fix anything. If there are errors then you will want to run the sfc /scannow to fix them. This should fix any major problems you are having with system files. When the sfc command is run it will also save a log file to C:\Windwos\Logs\CBS\CBS.LOG in this log you will find info and scan details that should help you know what the sfc command did and found.

If the SFC command line fixes don't work and you still can't access your files or programs don't worry you can still use the Check Disk tools (chkdsk), System Restore, or try Repairing your Installation of Windows.