What operating system is on it now, how much memory, and whats the video card on it? If it's got 4 gigi's of memory 64 bit Vista Home premium should not be a problem, though I also would like to know what processor you have in the laptop?
Also, it would be helpful if you could list the software you would like to run on it. That way if something does not work maybe a subsitute for it can be found.