Keep losing wireless connection on my PC??

I have a Dell inspirion 530s, with a wirless card, it just stopped receiving the internet connection after 12 months of being located in the same position in my house. I could still receive the connection through a laptop so know my ISP was not at fault. I narrowed it down to the wireless card and replaced it. Thats done the trick but now the connection keeps getting lost and says no signal. This is driving me mad, if I restart the computer the connection is there again. I have had no problems with the wireless in the past, it just seems to be on the Pc and not the laptop.