Can't Open Internet Explorer

You recently help me to remove a virus from a friends computer; the system is working fine, however we can not open Internet Explorer, only Mozilla!

This is the error message: Windows cannot connect to HTTP, HTTPS, or FTP. This is probably caused by firewall settings on the computer.

Please advise!

Thanks so much

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.