I'd start by finding the newest drivers - find the vendor name and model, and first check Gateway, then compare to the latest driver directly from the vendor.

I highly doubt it is a hardware issue - these things either work, or they don't - but it could be a loose connector. Most of these WiFi boards are in a MiniPCI slot, and if it is loose, it could drop the connection and not return till a reboot.

Hopefully a driver update / reinstall will do the trick.