Strange router problem

I have comcast internet a desktop and 2 laptops. Desk top is wired direct laptops are wireless ran off a lynksis router. The last 2 evenings my wife and I have not been able to access the internet from our laptops. At first we thought comcast was down but our desktop worked fine. We reset both the modem and router several times nothing helped. Both computers said we were connected to the net and at times we would be able to get to the homepage and then another site but within a few seconds we were done. We went to bed and it was fine the next morning. Then about 8 oclock last night same thing lasted all night. Woke up this morning it has been fine all day. Still is using my laptop right now

Any ideas