What would cause a new computer to not accept software installs and uninstalls?

My father-in-law bought a new HP computer (Vista Home Premium) and it will not accept software installs, won’t uninstall, and wouldn’t allow him to create a backup recovery disk either. He took it back to Best Buy, but they can’t see anything wrong with it (though it won’t work for them either). This computer is not even a month old.

They’ve suggested he call HP and buy a systems recovery disk. Is there anything we should try before he does that?