protable drives

is it possible to install a program to a portable drive and have it work on another computer correctly?

if it sticks dlls in the windows directory... or stuffs stuff in the registry. No.

Well... actually... if it's the same drive letter on both machines. You could install it on both machines to the same location. And it will work.

I hate it when games install stuff in folders outside of their own. Why do they need to do that? I can vaguely understand why apps might need to.