Computer Stopped Connecting To Router?

My wireless adapter shows that it is connected to my network, but my computer cannot connect to the internet. All other computers can still connect to the internet. It worked fine for almost a year, then one day...no connection.I use Windows 7, Home Premium, 64-bit; engenius wireless adapter and Linksys router. I tried to change to a TP-Link router, but my adapter (or computer) couldn't find it, so I switched back to the Linksys.Tried re-installing wireless adapter, linksys, tp-link; re-sets to both routers; uninstalling software, then re-installing;