I've got a couple XP partitions that seem flakey, perhaps just due to hit-or-miss Windows updates (some didn't go well--I noticed problems immediately after). I do have newer install CDs with SP3 merged, but I don't want to reinstall all apps if that can be avoided. Is there an easy way to do a "repair" installation from the XP SP3 CDs, over top of the existing XP installs? Goal being to keep all the existing apps. Secondary to this, I'd probably need to wipe the older keys, as the newer CDs have different keys. A regular repair seems to want the original install CD, which, in this case, would defeat the purpose.