Wierd problem: Gradual close down of internet access [fixes with a pc restart]

Ok on windows xp with one pc.
If it's left running for a few days,it's internet access gradually closes down across all browsers.
Closing zonealarm has no effect.

Google and boards are the last ones to go.

All other pc's and laptops are fine.No virus found with an up to date zone alarm or adware or anything.

The pc internet access goes back to normal if I restart the pc.

What could be causing this?

Biggins

What virus checker are you using?
Try installing the free Malwarebytes one (HERE) if you don't have it alrready.
One of the VERY best there is.

...and then run it once installed and updated.

Fysh

I've had similar issues with Zonealarm before - your best bet would be to enable the Windows Firewall, uninstall Zonealarm completely, reboot, then check if you can replicate the issue.

In the past when I've had the problem, uninstalling ZA, rebooting, confirming the problem was resolved, then installing the current version of ZA cleanly & rebooting again resolved it, so it's worth trying.