Wireless issue installing on Acer Aspire One Netbook

I installed win 7 on my acer netbook from xp and the wireless card seemed to be working throughout the setup. However, it stopped working after a few minutes and I can't even seem to find the wireless card in the driver manager to update driver. I downloaded the driver from acer and installed but no luck. Any help?

Tom

In device manager do you have any unknown devices? Or yellow triangles on devces?

No I don't. It's like it doesn't even exist anymore.