Not much to go on, but I will toss out a guess. You have 2 routers. One using the network 192.168.1.x (or similar) and one using 192.168.2.x (or similar). You put the 2.x into bridge mode and rebooted your computer. You computer now has a 1.x address. The bridged router still has the 2.x address. Your computer can't access the router because it's on a different network.