Required to hit Retry many times when running "sfc /scannow"

I have had some problems lately and thought it would be good to run sfc /scannow.
I have a full retail WinXP Pro SP2 CD so putting it into the CD-ROM is no problem. But this time I was required to hit Retry many times. That is something new and time consuming.
Attached is an image of the Windows\Set Up key in the Registry.
Can you see anything that should be changed? D:\ is my CD-ROM. C:\ is the drive where my OS is.
What about the entry for ServicePackSourcePath at C:\Windows\ServicePackFiles? And the entry for ServicePackCachePath? Should they be different? (Does anyone know what are the default settings for a fresh installation of WinXP Pro SP2?)
The similar key under WindowsNT just shows Source Path as D:\ . (The other SourcePath keys are not there, which I think is normal.)

 

As long as you have a folder named I386 at the root of the drive and the SourcePath set at just the drive letter ( so if you have c:\i386 the registry entry would be C:\ ) you should be good to go without needing the CD.

Two possible locations for the registry information though and you need them both to match.

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows CurrentVersion\Setup\SourcePath

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SourcePath

 

Newt--I knew that Arie recommends that in his article,
http://www.helpwithwindows.com/WindowsXP/howto-24.html
but since I have the WinXP CD it seemed to be no trouble to set things up to use it. But I certainly had a lot of clicking Retry this last time which meant I had to be present for much of the FileProtection procedure. (I actually had SourcePath at C:\ earlier which, as you say, is where my I386 folder is.)
I guess I always have been confused about sfc /scannow. I think it is supposed to find and repair corrupt or missing OS files. But if it is limited to searching the CD or the I386 folder (which I believe is created when Windows is installed and does not change with hotfixes and Windows Updates), then sfc is replacing bad files with old versions. The newest versions are in DLLCache. And yet no one says anything about having DLLCache as the SourcePath.
If you look at Arie's article, the first sentence says sfc "can be used to restore protected system files on your computer by using the backup versions that are stored in the Dllcache folder... ". Darned if I can figure out how sfc looks in DLLCache unless that is just built into the program.
P.S. It also seems that nothing usually is in ServicePackFiles until a new SP is installed over an old SP. In my case, I installed WinXP Pro SP2, so my ServicePackFiles folders are empty of bytes (although one has empty I386 and lang folders) since there has been no SP3 yet. So the only place sfc "profitably" searches on my PC is whatever is indicated in SourcePath. Unless it also searches in DLLCache as mentioned above.
P.P.S. Arie's article omits mention of the other (WindowsNT) Registry key. I wonder what happens if Source Path is different in the two Registry keys.

 

Jim - I'm not sure of the internal logic sfc uses so can't say for sure if the CD checks are only if there is no updated version or if the CD is checked for the original version number then the SP files are checked for a newer version and the most recent used or what. I also have no idea how the utility decides to use a dllcache version or a CD version or ????

I do know that if you put I386 on the hard drive and point the registry entries to it, you can simply start sfc /scannow and it will do it's thing without asking you for the CD or making you click retry. The little space used and the little time to tweak the registry was worth it for me to avoid the hassle of doing a repair when the CD was needed.

 

Newt--Agree using C:\ for SourcePath is easier (assuming your I386 files are in C:\ --some peoples are not). Just wonder what running sfc that way does.
Sfc is not the most communicative program. Does a smooth run through without being asked to Retry mean anything has happened? There is no log so you never know. And what is happening when you are asked to Retry? (Don't expect an answer, just wondering. )

EDIT--Just read http://support.microsoft.com/?kbid=222193 and apparently SFC does search in DLLCache by default.
"The WFP feature provides protection for system files using two mechanisms. The first mechanism runs in the background. This protection is triggered after WFP receives a directory change notification for a file in a protected directory. After WFP receives this notification, WFP determines which file was changed. If the file is protected, WFP looks up the file signature in a catalog file to determine if the new file is the correct version. If the file is not the correct version, WFP replaces the new file with the file from the cache folder (if it is in the cache folder) or from the installation source. WFP searches for the correct file in the following locations, in this order:
1. The cache folder (by default, %systemroot%\system32\dllcache).
2. The network install path, if the system was installed using network install.
3. The Windows CD-ROM, if the system was installed from CD-ROM.
If WFP finds the file in the cache folder or if the installation source is automatically located, WFP silently replaces the file. "

Unfortunately no explanation of what Retry means when you use the CD, and why you do not get any similar message when you use C:\ as SourcePath.