Full of Viruses Avast Isn't Removing

[REDACTED]

Seems my teenager surfed into junk and cannot get the bad stuff off my computer.  "Rootkit: hidden file" is infecting a number of my files.  How do I get rid of it?  Thanks!

[essexboy]

DO you have the file name and location

Please download Farbar Recovery Scan Tool and save it to your Desktop.
 
Note: You need to run the version compatible 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.
 

• Right click to run as administrator (XP users click run after receipt of Windows Security Warning - Open File). When the tool opens click Yes to disclaimer.
  
• Select  additions at the bottom
• Press Scan button.
  
  
• It will produce a log called FRST.txt in the same directory the tool is run from. 
  
• Please attach both logs generated.