Hard to say, SP3 might not even install on your modified setup. The service pack only updates select files and adds some features, it doesn't reload the whole OS. It's a bunch of updates, etc. I'm not up to speed with nlite so I don't know if it actually strips the features off of the install image or just prevents them from being installed. If it just prevents them from being installed you should be able to put them back from add remove programs. Try it anyway the worst that will happen is you get an error when windows can't find the files on the CD. I'd install SP3 anyway just for security reasons.