[Andrew G. N.]

Are you on a wireless connection? I used to have an HP notebook that would lose the connection the way you described. Upgrading to Windows XP Service Pack 2 fixed the problem for me as SP2 does a better job of keeping a wireless connection. If you're not on a wireless connection, try plugging right into the modem and bypass the router. If that fixes things, check to see if your router has new firmware available. If not, try uninstalling/disabling any internet security suites you may be using. If none of that works, it could be a virus or key-logger taking up your processor cycles.