This startred recently (past few days). Been using this card for years with 0 issues. A few days ago I started getting the yellow triangle w/ the ! over the wifi signal icon stating that i was having wifi issues. The way I would fix it was mearly disconnecting the card and reconnecting it or ipconfig /release -> ipconfig /renew. Well yesterday the commands werent working so I went to disconnect the card and when I reconnected it my computer didnt recognise it. So I uninstalled it from device manager and reinstalled it and it said there was an error while installing drivers and the device isnt working. So I plugged it into several other computers and the card worked. Not really sure whats goin on. Downloaded multiple drivers from various websites for the AWUS036H and RTL8187 and nothing worked. Im sure I can just reinstall Win7 and it will be fine but I want to leave that as my last option.
Did you try inserting any other card into that slot? It could be mobo/slot related (as in, defective slot, etc.). If it's Win 7 it would most probably be a driver issue (are any of the computers your tried it on have Win7 64-bit as well?).
The card doesnt come with drivers to uninstall. All I did to install was plug the card in and Win auto installed the drivers.
I registered to this site to help you out OP. Have you tried installing the windows 7 drivers from alfa networks? Sadly I can't post links but if you go to their site and download the "Power Control" Drivers you may be able to fix your problem. I also believe the driver from them is newer/updated version than the one that comes from Microsoft. google "alfa networks" I have the usb version, but I never heard of a pci slot card version it