Windows XP: Is this a bad driver issue? "Enter Key" stops working periodically

Is this a bad driver issue? "Enter Key" stops working periodically

I think this is an OS issue, not a HW issue.

Periodically, both "Enter" keys on my stock Dell keyboard stop working (both the standard enter key & the enter key on the numeric kepad on the right). I have swapped in a known good keyboard, but the enter key continues not to work.

The system is a stock Dell desktop (1.8 GHz Centrino, Windows XP) with Dell keyboard, Dell monitor (motherboard graphics), Dell mouse, Dell 802.11b USB wireless ethernet adapter.

Sometimes, a reboot fixes the problem... and then it reappears.

In an attempt to fix this problem, I have uninstalled the keyboard driver & allowed the system to reboot so that Windows "finds the new hardware" and then installs a new driver, and reboots... this solves the problem for a while, but then the problem returns.

I'm at my wits end! Any ideas on what I might do to fix this issue?

Thanks