I always like to do as much fixing as possible in a non-destructive way - but it does sound as if we may have to do something a little more drastic.
I'm assuimg here that you can accessall the normal sites - *including* www.symantec.com www.microsoft.com
without a problem, and that Kaspersky is happily updating itself?
Start by running Fixit 50123 from here Error codes
Reboot and retest
Then download Fixit 50202 from here... How do I reset Windows Update components?
- NOT the popover one, but the one in the KB article.
Run it in normal mode first
reboot and retest
if you're still failing, run in Aggressive Mode
This will delete your Update History, but not the list of Installed Updates
reboot and test