Yeah this is the forum for cpu problems, yours is a network problem. Anyway....
Loosing a wireless signal can be many things. How far away is the pc from the base station? The further away the poorer the signal and the liklyhood of it being lost altogether. Do you have any other 2.4ghz appliences in the house? Maybe a digi sender or other similar device that could be interfeering with the signal. Try mooving the pc closer and see if it keeps disconnecting. Also are you using the correct driver?
Just a thought, if it worked fine before for some time and now it doesn't, check with your neighbours, up, down (if you're in a flat) and next door. They might have a wireless device in their house interfearing.
Hope that helps
Never trust a man who, when left alone in a room with a tea cosy, doesn't try it on. - Billy Connolly