My PC freeze up - avast

Hello guys, I need help.
I want to scan my PC so I download avast! Free Antivirus and I started fast scan. Avast detected these infected files: (C:/Program Files (x86)\SO_Booster\AssistantSvc.dll) (C:/ProgramData\AppSlow.…\SO_Booster.exe). Seriousness is high. I decided to clean automaticaly both of them. But then my PC freeze up. I tried to press Ctrl+Alt+Del but my PC doesn’t react. Could you help me please?

Hi,

Please download Farbar Recovery Scan Tool (
http://www.mcshield.net/personal/magna86/Images/FRST_canned.png
) by Farbar and save it to your desktop.

Note: You need to run the version compatibale with your system. If you are not sure which version applies to your system download both of them and try to run them.
Only one of them will run on your system, that will be the right version.

[*]Double-click to run it. When the tool opens click Yes to disclaimer.
[*]Press Scan button.
[*]It will make a log (FRST.txt) in the same directory the tool is run. Please attach it to your reply.
[*]The first time the tool is run, it makes also another log (Addition.txt). Please attach it to your reply.