Why is this happening to my wireless ?

Ok so I got Internet like a week ago I got the cisco linkysy or something like that router and a black little motorola modem or whatever...and I was playing black ops online like 3 days ago on wireless and then I tried today and It fails and says something like an error has occurred but all the green lights are on on my modem thingy.......what do I do???to get wireless again..and I will say that they both got unplugged but plugged back immediately