http://www.westelcom.com/users/rogersr/sfc.htm
System File Checker explained......(hopefully in layman's terms)
System File Checker, or sfc.exe, is a very handy tool that is part of
Windows 98 which is often misused (which is likely why it was removed from
later versions of Windows). It's primary usefulness is in extracting files
from the Windows CD. It is often misused to identify corrupted files.....
The problem is that System File Checker does not know the difference between
a corrupted file and an updated one. Many system files are updated with a
newer version via a WindowsUpdate session or by the installation of an
upgrade to Internet Explorer. When sfc is used to scan for altered files, it
only knows that the file has changed in some fashion, and thereby identifies
it as "possibly corrupt".
What happens then is that a user is then prompted to replace the "possibly
corrupt" file with a new one from the Windows 98 CD. This is not a good
idea, as it will be replacing a newer version of itself that was created by
an update. By replacing a newer version with an older one, something is
bound to go wrong. Some function or other will call for that newer version
and, of course, will not find it. This will result in an error message like
"XYZ is linked to missing export ABC....", and the program will not run.
Another frequently seen error is the misguided advice to use it to extract a
new vmm32.vxd file due to an error message listing that as a potential
problem. This .vxd file is a shell that contains other needed drivers and is
built during an installation. Extracting a new vmm32.vxd from the Windows 98
CD is replacing a system built file with an empty shell. Guess what's going
to happen when the system calls for a driver contained in that file (or in
some cases - drivers)......... My advice? Don't do it.
Ok, so enough of the bad, now for some good:
The best way to use System File Checker? Simple, when your system is running
just the way you want (don't laugh, it does happen), run sfc, and for each
file that it identifies as possibly corrupt, choose the option to update.
Then, if something does go wrong, you can scan for altered files and those
identified as "possibly corrupt" may very well be, and should be replaced.
The challenge there is knowing what file version it is and where to get the
right one from. There is a fairly useful database published by Microsoft,
but it has been known to be incorrect at times. Still, it's better than
nothing.....
http://support.microsoft.com/servicedesks/fileversion/dllinfo.asp
For more on System File Checker, see these Knowledge base articles:
Description of the System File Checker Tool (Sfc.exe)
http://support.microsoft.com/default.aspx?scid=kb;EN-US;q185836
System File Checker tool extracts incorrect file versions
http://support.microsoft.com/default.aspx?scid=kb;EN-US;q192832
How to extract original compressed Windows Files
http://support.microsoft.com/default.aspx?scid=kb;EN-US;q129605
Fanblog said:
Per suggestion, I ran "sfc /scannow" from the Windows Task Manager to
recover missing/corrupted system files. When I did this the first time, it
spent at least 30 minutes copying files from my Windows XP CD (that's what I
think it was doing). But after I restarted my system, I got the same
"Unable To Locate Component" error re: a DLL file at bootup time.I then ran "sfc /scannow" a second time, and once again it took another 30
minutes to copy files from my XP CD.
After I restarted my system, I continuted to get the same error message as
before.I've looked at the syntax of the sfc utility and can't
figure out what else I need to do (good article at
updatexp.com/scannow-sfc.html). Would "sfc /purgecache" do the trick? I
also read something about editing the registry--do I need to tinker with
that?I posted my original problem on 2/24 around 7:35 pm--if it's still there.
