BleepingComputer.com: Stupid Download mistake

I was stupid and tried downloading a game online, where I had to get a keygen with it. I'm not completely computer illiterate and had scanned all files with everything I've got. Antivir, Windows Defender (which I know is crap), and a malware program.

My problem now is that I have the keygen program coming up randomly, firefox.exe is always running, and now a new problem. A logan estudos Operating System thing that runs in the background and won't go away. I've scanned everything, went through and tried to delete it manually but it keeps coming back. The only time the keygen program doesn't come up is if I disconnect my internet. The others are continually going.

What do I do? I'm getting very frustrated and don't want to have to reinstall my OS.

Hello...
You will need to run HJT/DDS.
Please follow this guide. Preparation Guide For Use Before Using Hijackthis. Then go here HijackThis Logs and Virus/Trojan/Spyware/Malware Removal ,click New Topic,give it a relevant Title and post that complete log.

Let me know if it went OK.