I have a Trojan called "vundo"
how can I get rid of it.
I can not open Internt Explorer

Run a virus scan. Once the AV detects the annoyance, either delete it or cleanit. Whatever the AV offeres.

I recommend Nod32 even if you have to use just the trial version.

As the specific Malware mentioned came out in 2004, It is up to you to keep your anti-virus/malware applications up to date. If you did so, you'd not see this on your system, and messages sent to you would automatically be quaranteened.

Gerritt