You could possibly have a hardware conflict. Try uninstalling the USB adapter, then if it stops crashing, the USB is the problem.

Instead of buying a USB adapter to gain the signal better, try replacing the antenna with a stronger one. If your card's antenna is detachable. I have found that to be the easiest, cheapest, and most simple solution.

ps. the repair connection option in windows has never fixed any of my problems. And it also sometimes locks up with me.

Borgslayer