Wireless Internet Connection Problems

I have a Dell Latitude D600 running on Windows XP with an integrated Intel Wireless LAN 2100 and a Netgear RangeMax Wireless router.

Everything was working fine up until about 3 months or so ago. Now I lose the Internet Connection if I'm away from the laptop for over an hour or so. Certainly overnight or when I return from home.

When I run the Window's "repair" Internet Connection utility, that resets your IP address, clears you cache, etc., the Internet Connection is restored and it works fine until the next time.

This issue just started happening a few months ago and I can't figure out whether it's the router, Time Warner Cable or this old laptop. I haven't done anything to the router & TWC says there's not a problem with the cable Inet connection nor I have I done anything with the computer (that I'm aware of).

I'm thinking this is a computer issue, though, since my newer Dell Latitude from work doesn't seem to have this issue.

Any ideas?

Thanks!