Could you fully uninstall Avast using the removal tool please
Avast Uninstall Utility
NEXT
Run delfix but just select “Remove Disinfection tools”
This will remove FRST and Combofix quarantine folders
Download and run Delfix
https://dl.dropboxusercontent.com/u/73555776/delfix.JPG
Reboot once done
Then
Copy the following to a notepad file
Select save and set the file type to all files
Save it as IFEO.reg
Save it to the desktop, then right click the file and select run as administrator
Accept the warnings and reboot
Windows Registry Editor Version 5.00
[-HKEY_LOCAL_MACHINE\software\wow6432node\microsoft\windows nt\currentversion\image file execution options]
[-HKEY_LOCAL_MACHINE\software\Microsoft\Windows NT\CurrentVersion\Image File Execution Options]
Finally
Could I have a fresh FRST scan
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.
https://dl.dropboxusercontent.com/u/73555776/frst.JPG
[*]It will produce a log called FRST.txt in the same directory the tool is run from.
[*]Please attach both logs generated.