nLite is fun......particularly when 'excluding' bits of XP that you don't want to install/use.....I did it on Terry's machine ages ago....worked just fine....
On my machine I have Drive Image doing an auto image once a week.....[does it natively in Windows]....and the only thing to keep an eye on is 'space usage'....each image is around 6 gig....[20 gig OS partition].....but you just delete various older/unwanted images.
It's a bit like having rather 'extensive' system restores. Then all you need is a second physical HD...with same size OS part...and Image to that drive....put both in caddies and you have an instant OS backup that need not be any 'older' than a week....time to switch?....the time it takes to shutdown, swap, and reboot.
Works a charm...