I have Kaspersky Internet Security v7.0.1.325 c.d.e installed on my Win XP Pro SP3 system. Just recently Windows Security Alerts tells me that my virus protection is off. Kav is, however, on.

Can anyone please give me a reason why this error is occurring?

Dear friend,
Please try to doing following..

1. Temporarily disable the WMI service (Windows management instrumentation) in: Start >Run > type: services.msc and in there find/stop WMI

2. Next delete the C:\windows\system32\wbem\repository folder, wait for it to recreate (can take a bit of time)

3. Restart the WMI service & restart the computer

and answer us if problem be solved or not.
Best Regards
Cain Chen