av security removal

I earlier requested help with removal of av security suite. I have a compaq desk top with windows xp media center 2005. The answer I was given was to download OTL and run it. I am communicating from another computer because the virus or whatever won't let me get into anything on the infected desktop. It keeps popping up the file is infected. Access to my e-mail is also locked out. I was able to get into tools and start the process on AV security suite removal guide but I don't have firefox so I don't know if that is why I can't proceede past the "use the proxy server for your lan" function. I couldn't find a apply button to hit after I hit ok How do I even start? Thanks

We are going to be using a Windows Recovery Environment to help disinfect the system so it may boot again.

Download the OTLPE Standard REATOGO Windows Recovery Environment.

• Place a blank CD-R disc in to your CD burning drive.
• Download OTLPEStd.exe and double-click on it to burn to a CD using ISO Burner.
• Reboot your system using the boot CD you just created.
  
  Note : If you do not know how to set your computer to boot from CD follow the steps here
  
• Your system should now display a REATOGO-X-PE desktop.
  
• Double-click on the OTLPE icon.
  
• When asked "Do you wish to load the remote registry", select Yes
  
• When asked "Do you wish to load remote user profile(s) for scanning", select Yes
  
• Ensure the box "Automatically Load All Remaining Users" is checked and press OK
  
• OTL should now start. Change the following settings
  • Change Drivers to Non-Microsoft
    
  • Press Run Scan to start the scan.
    
  • When finished, the file will be saved in drive C:\_OTL\MovedFiles
    
  • Copy this file to your USB drive if you do not have internet connection on this system
    
  • Please post the contents of the OTL.txt file in your reply.