Trouble removing System Security software

I followed the instructions to download the suggested software to remove the System Security Software on one computer and it worked well-Thank you! However, I am trying to do the same on my other pc and once I download the removal software it will not let me open it, which is what it is doing to all my applications! Any alternative suggestions on how to remove this software?
Thanks

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.