help me i have anti virus pro and need it gone!!!!

Plz help me! Can't get rid of antivirus pro. I used malware to scan, removed infected, restarted an now I'm getting pop ups, baloons filling up toolbar and it won't let me connect to any websites! Plz help me
i have windows vista too. is there a program i can use to download.

Please download the current version of HijackThis from HERE

• Double click and run the installer.
  
• It will install to C:\Program Files\Trend Micro\HijackThis\hijackthis.exe
  
• After installing, you should get the user agreement, press accept and Hijack This will run.
  
• Select Do a system scan and save a log file. This will open a notepad file of everything Hijack This found, copy and paste it back here.