I recently reformatted my HD, and when I went to get online, my wireless connection no longer works. I can connect to the network just fine, but I get the notice that there is "limited or no connectivity." I can get online running an ethernet cable from my router to my PC. I have reset the router, but to no avail. When I try to repair the connection via the Network Connections option under Control Panel, I get an error message saying, "Windows could not finish repairing the problem because the following action cannot be completed: renewing your IP address." when I try to renew the IP address via the command prompt, I get an error saying, "An error occurred while renewing interface wireless Network Connection: unable to contact your DHCP server. Request has timed out."

I get the same problem with two different routers--a Linksys WRT54G and a Linksys WRT160N. I have downloaded and installed the latest drivers for both my wireless card and the routers. Any suggestions on how to get the wireless connection working again? Thanks!

Check you encryption key

Can you ping your network card?

In a CMD prompt try this command
Ping 127.0.0.1
If you get a response then your NIC should be fine, and the issue is elsewhere
If not the issue is coming from your NIC. You stated that you recently reformatted your PC. Are you sure you have the correct drivers installed for your NIC?

You could also try releasing your IP before renewing it.. I realize that you don't have an IP to begin with but it's worth a shot try this command
Ipconfig /release (enter)
Ipconfig /renew

Also make sure you have no other software installed that is meant for connecting to wireless networks. This will interfere with the windows default service. In your services manager (found by righ-clicking on my computer and choosing manage) go to services -> scroll through the list until you find the service called wireless zero configuration.. If it is stopped right click and start it. If it is running right-click and stop it then right-click and start it again (you should probably reboot after this as well). Let me know if any of that works

Go into your preferred networks and delete the connection you're trying to access. After doing this, try and connect to this connection again. You will be prompted to re-enter your passphrase (if applicable).

The reason I say this is because it's not likely your router(s) if you can connect physically. This shows us that DHCP works fine and it's an issue with your PC.