I bought this a few days ago because while I already own a copy of it I like not having to dig for my discs when I wish to install. I was wondering if there is a way to make the game work off of a thumbdrive because I would like to play while at work. However, whenever I try and run the .exe it gives me a "Your CD key is invalid. You will need to reinstall the game and enter your CD key to fix this problem." message. Does anyone have any ideas on what I could do?

Try installing Mojopac on your thumbdrive (google it, it's free), then install the game from inside the program.

mojo the music sharing program? google did not help us.

*Mojopac, sorry http://www.google.com/url?sa=t&source=web&ct=res&cd=1&url=http%3A%2F%2Fwww.mojopac.com%2F&ei=PLfGSf7LC5C0jAexn-CPCw&usg=AFQjCNGN1hE7aR3Af4ViSOdd1zARdliEOw&sig2=ZVpGhEWIigHbnw5MY1HXcQ

that appears to be a GREAT solution. :D

Great indeed, if it actually works. From browsing their boards, apparently work on mojopac has been slow in the last few months. Can anyone try and see if it works, either ut2k4 or any other game, in a flash drive or removable HD and connect it to a host computer and see if you can play from there? Single as well as multiplayer?
EDIT. Do NOT try this. I just installed it and it crashed my pc, i had to do a cold reboot. This is a buggy POS, and it seems to be abandoned by its original developers, avoid at all costs.

I had that same problem with the discs. If you use this
[url=]http://www.filefront.com/13629146/Registry-Fixer-1.3/[/url]
you can enter the cd key, and other information like exe locations.
It works without admin privileges, I use it all the time on school and library computers without fail.