Multiple Virus Popups - Installed McAfee but nothing helps, where do I start?

I was getting porn popups on XP. Finally I installed McAfee but then it got worse. I now get multiple popups about needing to install Malware software and it wanting to uninstall McAfee. I tried safe mode, etc.

Not sure what to do from here but putting myself in your hands. Please guide me through.

I have a list of what viruses/malware it says I have including chin09.win and virus.win32.gpcode.ak, etc but not sure if they are really on my machine.

Help

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.