Any backup copies I've made have worked just fine, whether they were created with Nero or with CloneCD. You're actiually using a CD copy routine, are you, and not just dragging/dropping the CD contents from one drive to another?
Mainly to include service pack 1 or 2 as my original xp pro has no service packs; and also if i recall correctly when i tried backing up with Nero or clonecd or cdrwin i always ended up with a cd that wouldn't boot or prompted for files from the a: drive. Must have missed a setting or something; all i know is Bart's way worked for me first shot and i don't have to immediately update on a reload cuz i'm going directly to XP Pro SP2.
P.S. I'm one of those people that ' if it ain't broke, tweak it!' I don't use System Restore and my best cure for any computer headache is a clean install.
I forget the exact terminology for it, but you can do a technique called "slipstreaming" to include service packs, applications, or other items into the standard Windows installation media. Try doing a Google search for that.