Virus - unable to run any malware tools! Help!

So... I am completely clueless about computers. I got this virus by downloading a torrent grr.
I cant follow any of the removal steps because it won't let me open up anything, any programs or the internet, and it keeps on sending me to this website, "antiviruspower."
I can't open task manager or open Remove/uninstall programs, open command prompt, go on the internet, open microsoft word or anything of the sort.

"Application cannot be executed. The file ___ is infected. Do you want to activate your antivirus software?"
(if you say yes it takes you to the 'antiviruspower' website...)

I am on a mac right now, since I cant go onto the internet on my other computer.
I downloaded the virus removal stuff (from the removal steps) onto a USB so I could try to install it on my infected computer but when i try to it gives me that error message, above.
I can access task manager by taping down the control alt delete buttons so it will keep on opening new ones but I don't know if deleting processes from the task manager will help anything, I'm completely clueless. Before, I deleted some random processes that I thought sounded weird... i hope I didn't ruin anything.
It helped once though. I deleted something (dont remember the name) and after that the virus seemed to be gone, except I couldn't go on the internet. then, since I could open things again, I followed Step 1 (I installed TFC) and when I rebooted like it said, all the virus stuff was there again and nowww, I cant do anything again...
Maybe there's a malware removal program that doesn't end in .exe? maybe that might help.

I need to use that computer for school. I have very important stuff on there. Please help, thank you SO MUCH if you could.