Question about System File Checker.

I'm planning to help a friend set up SFC to scan from her Hard drive, rather
than be reliant upon the Install CD.

Like me she's using XP Pro SP -2 Retail. In order to make sure I have all
my bases covered (and because I've done this before with an OEM build of XP
that had been upgraded to SP2 with a slipstreamed disk I made,) I changed
the registry values on a clean install of XP Pro SP 2, following directions
provided by Marc Liron at www.updatexp.com.

When I went to test SFC /Scannow... I was prompted for the Windows
installation CD to rebuild the DLL Cache file. So I went back into the
registry to see what else I could have missed - needing changing.

In HKLM\Software\Microsoft\Windows\CurrentVersion\Set up
the item ServicePackCachePath is pointing to
C:\Windows\ServicePackFiles\ServicePackCache ... which is a folder I've
determined to be non-existent in C:\Windows - after showing hidden and
protected OS files So taking a guess I changed that value to C:\windows.
Also In Setup - the SourcePath and ServicePackSourcePath are both pointing
to C: - and in
WinNt\CurrentVersion\Winlogon the Sourcepath is also set to C:\ because
\i386 was copied to C: from the install disk.

I'm still getting the same message to insert the CD. Is there someone who
can help me get this straightened out?

Thanks much in advance.