Desktop computer, connected directly into a Comcast modem. Every so often, at seemingly random intervals, my connection will drop. This could be while in the middle of browsing, or when I'm not even at the computer. When the connection drops, the modem still shows 4 green lights. The modem is connected to a splitter (cable and internet in same room), and then directly to the wall.

To recover from the problem, I am forced to restart my computer, at which point everything works fine again.

I have tried an ipconfig/release and renew, it tells me that it is unable to contact the DHCP server, and thus can't renew. I have updated the NICs driver, no luck. I have changed the ethernet cord, no luck. I have had Comcast replace the modem, no luck. The only thing I can think of that hasn't been replaced is the cords connecting the modem to the wall and the splitter. Can anyone think of anything else I may be able to do to isolate what's causing the issue?