Random internet disconnects and reconnects

New user here, I have an acer aspire 5739g running windows 7 64bit. Acer provided free upgrade from vista a couple months ago. Got the laptop back last july 2009. Just recently though i have been getting a lot of random internet disconnects, about every 5-15 minutes. I initially had a netgear router setup. I tried using the wifi from it only instead of direct wire and same thing happens. I then directly connected my laptop to my comcast modem and the same thing still happens.

When it disconnects the network and sharing center shows me still connected to the network but on the line going to internet there is an X on it and i am cut off from internet for about 10 seconds to infinity at which time i restart the laptop and it usually fixes itself. I turned off the homegroup which hasnt done anything and the wifi and ethernet drivers are both up to date. So at this point its either my comcast, which I still am trying to test out with my old computer loaded with xp, or my laptop with which I have no idea what to do with other than try it with someone else's internet. I think its the laptop. Sorry for sloppy english. Any questions about system and I should be able to find it out.