Just update the game, then archive the game folder. Unzip anywhere, anytime.
A little confused about registries and such.
Let's see.
1. Install game.
2. get patch from 'net
3. zip it up and archive it.
4. uninstall.
-------------- LATER -----------
1. install game.
2. get patch - DANG no more Arcen
3. unzip the patched game right on top of the game I just installed.
That would work and wouldn't screw up anything weird stuff in Windows that I don't know about?