RCA DCM425C

What it sounds like to me is that your router has been running for a while, and thus start to break down slowly. You coul try power cycling it.

power cycling:
1.) Only unplug the power cord from the modem only, for about one minute.
2.) After one minute has passed, plug the power cord back into the modem, give it a few seconds to boot up again, and it should work.

If the modem still does not work, then the problem might lie with the computer itself, very hard to see happen, but it could still happen.
If in then that case, you would have to system restore your computer to an earlier date. that it was working fine on.