|You shouldn't need to buy a new wireless card, Windows Vista and Windows 7 are pretty similar as OSs, this is not like the jump from XP to Vista. |
I would check Device Manager for driver issues. It may be as simple as downloading the Windows 7 driver over the Vista driver. Lots of times you can use a Vista driver in 7, or vice versa, but not always. In your case it doesn't sound like you can.
If you bought this from Netgear, it would be worth it getting in touch with them to see what they say about your problem.
In your situation if you can fix the problem without buying a new router at all, that would be ideal. Good luck.