I'm being targeted by many trojan attacks, whenever I start windows the computer beeps and I get the message from norman av that it has detected the attack and put it under quarantine. but after removing it, it comes more, W32/Vundo.dfo etc the origin says 192.168.0.103
I've tried virtualmundobegone but it does not help. Any suggestions? What is this problem and how do I solve it?

Run a full system scan with SuperAntiSpyware in Safe Mode.

How to start Windows in Safe Mode

I did get rid of some, but I accidentally removed some things I wasn't sure of by using hijack this, and now the tool bar is missing lots of things :/ it doesn't show norton nor the automatic update icon and some other things :/ Is there a way to get them showing again? They are still on the computer. Will I have to re-install all those programs because I removed some important files through hijackthis? The viruses seem gone and the trojan attacks ended, but the computer doesn't feel right..

See the following post:

HijackThis Tutorial - How to use HijackThis to remove Browser Hijackers & Spyware

Scroll down to Section 4: How to restore items mistakenly deleted.