Strange behaviour after virus removal

Hello

My computer got infected with winupgro.exe virus and here’s what it has done:
– prevented Norton Antivirus to load at startup
– prevented ZoneAlarm to load at startup
– blocked my web browsers (IE, Firefox) to the internet
(Outlook Express was working).

I deleted the virus and its copies manually but strange thing, now the sympthoms remain the same!

So the browsers can’t connect to internet, and NAV and ZA don’t run.

I tried to run the instalation kits again, to repair the damages but they can’t be run by the system, which says they’re not valid 32 bit applications!!!

I don’t know what to do next… any advice appreciated.

Thanks.