Beyond what genius_at_work suggested, I'd recommend restarting the modem and router. To do so, turn off both. Then, turn on just your modem and wait until it is fully started. Then, turn on your router and wait for it to fully start as well. Then, try using the internet. It may just be coincidence that your "lease" to your IP on your router expired while you were uninstalling and it needs to be reset.
The shorter method is to type the following in Start>Run:
ipconfig /release
ipconfig /renew
(those are 2 separate things to type and hit ok for). The first solution is more likely to succeed, but this one is faster if you want to try it.
