I took my XP CD that had SP2 slipstreamed on it using nLite and slipstreamed SP3 on top of it. Completed okay, but would not install, missing many files. Tried it a few different times, thinking I had removed or deleted some things that I should not have but it made no difference.

Finally, I went back to the original XP Pro with SP1 then slipstreamed SP3 on that and it works great. Installs fine, no missing files.

So the moral of this story is, don't slipstream a service pack on top of a XP CD that already has a slipstreamed service pack on it.

a very good piece of advice.
slipstreaming isn't without its minor setbacks as well... when correcting problems with the computer, if certain registry keys have not been updated, the computer can ask you for the windows CD, in a loop, as it wont be looking in the right location...

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Setup\SourcePath

make sure that entry points to your CD drive letter. Alternatively, you can copy the i386 folder onto your harddrive and point it there.

also, make sure that ServicePackCachePath and ServicePackSourcePath both point to the correct location, usually C:\Windows\ServicePackFiles


Just thought I'd pitch in my personal experience with slipstreaming

On my system, after installing SP3:

ServicePackCachePath points to C:\Windows\ServicePackFile\ServiePackCache
ServicePackSourcePath points to C:\Windows\ServicePackFile

yeah, in my experience both those registry keys should point to the same folder, C:\Windows\ServicePackFile
the key that has the extra \ServicePackCache will know where to go from within the \ServicePackFile folder... if you point it directly it gets confused and causes the problem I described

It installed without problem for me, on two computers, and both have the entries I posted.