linksys wireless adapter and windows 7?

[Theeva]

i bought a wireless adapter for my desktop and want to use the internet however i can't because the adapter says error driver cannot be installed. is there anyway i can install this because i dont think i can take it back and i cant ring the tech support because i live in new zealand and it would cost so much to call i might as well buy a whole new adapter. thanks in advance i can add any more info if you need it