Internet Applications - Blocked access

[patkim]

I wanted to try out a new Antivirus Software Quickheal and after install, realized that all internet applications were blocked from accessing net. I also disabled the firewall on Windows XP Sp2. Also removed that software but now though I get connected to net, practically can not use any Internet applications. They refuse to open/access the site etc

Before I plan to reinstall XP, would like to know if anyone can suggest any possibilities to overcome this

The new antivirus deleted some DLL file from my PC reporting that it had virus. I also realize that when PC boots some executable named Rundll32.exe autostarts. This is located under Windows System folder.
Is this a valid Windows file or some kind of spyware, virus etc.

My OS is Windows XP Pro SP2

Thank you.

[Gecko]

There are a number of thing that could cause this, host file, winsock, BHOs…
Please download , unzip it to it's own folder.
Start HijackThis and select 'Do a system scan and save a logfile'
Now copy the contents of the logfile and post it into this thread.