Windows error?

"file c:\windows\system32\config\system missing"

This could also make reference to the files sam, software, security, or default. This error is caused by one of the registry hives becoming corrupt. To fix this, you can try the easy way first: using a Windows installation disk, boot from the CD or DVD and navigate to the "repair" option. This varies a bit depending on the operating system. In Windows XP, you will be asked if you wish to repair the computer using the recovery console. Windows Vista and 7 are a little different?asking if you wish to repair your computer. Your task is to get to the command prompt, so choose that option in Vista and 7.
Once you get to the command prompt (C:\>), type CHKDSK. Ttype CHKDSK /R. This will scan your file system for errors and just may fix the problem. Once it is finished, reboot the computer and see if the problem persists. Many times, you will succeed.
If this doesn't work, you may have to reboot from the startup disk and do a Windows repair or reinstall (the choices depend on what system disk your computer manufacturer has provided). The prompt for the Windows repair will come after you answer the question asking if you wish to use the recovery console and you choose not to do that. You will have to press F8 to accept the terms and conditions and then you should be asked if you want to repair a Windows installation. Choose that option and you can do a repair. Once you choose this option, you must select the copy of Windows to repair (normally choice #1). It will ask you for the administrator password. If there is no password, just hit RETURN. If there is a password, enter it. If you don?t know it, proceed to the next step, below.
It?s possible at this point that your computer manufacturer?s disk will not allow this option. It may want you to only install a new copy of Windows. This is OK to do, and if you choose it, be sure to tell the computer to install it by leaving the file system unchanged. What will happen is that you?ll have a new Windows installation, your data will be intact, but you will have to reload your programs.