Some initial thoughts:
1. Even though your iPad can use the wifi from your router (whereas your PC can't), it might still be a router problem. Yes, I know that would appear to be counter-intuitive but sometimes a router can't correctly allocate an IP address to a device. So it's still worth trying the old trick of 'switch it off, wait and switch it on again' with your router. It's amazing how often it works!
2. Are you sure that your PC is designed for use with wifi? The majority of PCs are probably still sold without a wifi adapter inside. So they won't work via wifi unless a wifi adapter (or USB dongle) is fitted to them.
3. Have you tried connecting your PC to your router via an Ethernet cable? Your success, or otherwise, in doing so might provide us with some clues as to the nature of the problem.
4. Assuming that your PC actually has a wifi adapter installed, have you actually tried connecting it to your wifi by searching for the signal, connecting to it and entering your wifi password? (It's not going to happen automatically if you've not already got it set up). If so, at what stage does the process go wrong?
Information, please!