How to Get Rid of System Tool Virus for Free?

How do you get rid of the System Tool Virus for free? I'm not a very savvy troubleshooter and could use some help.
My computer is running Windows Vista and it got infected with the System Tool Virus.

I have the Mcafee anti-virus installed but it's not working, I tried to download another one but I can't.
The virus has stopped me from going onto the internet. Can anyone please help me remove the System Tool Virus? Is there a free fix?

Well, I got infected by the System Tool Virus too and I'm running Windows 7. In order to remove it I restarted my computer in safe mode and did a system restore. That's all it took.
Also, McAfee will work in safe mode and it will let you delete the virus.

The System Tool Virus resides in c:\documents and settings\all users\application Data\[Folder with weird name]\foldername.exe.
If you delete that folder, it will be gone.
BE CAREFUL, don't delete any file if you're not sure what you're doing and do it at your own risk.

System Tool is one of the worst virus. It takes away your internet, it blocks all removal attempts, it stops your antivirus from finding it.
I restarted in safe mode, downloaded Malwarebytes and run it. It found the virus and I was able to remove it from my PC. I'm running Windows XP.