Please download
OTMoveIt by OldTimer and save it to your desktop.
Next, double-click OTMoveIt.exe to run it. Copy the file path below to the clipboard by highlighting it and pressing CTRL + C (or, after highlighting, right-click and choose copy):
c:\windows\system32\drivers\srosa.sys
c:\windows\exefld\
Return to OTMoveIt, right click on the "Paste List of Files/Folders to be moved" window and choose Paste.
Click the red Moveit! button.
Copy everything on the Results window to the clipboard by highlighting ALL of them and pressing CTRL + C (or, after highlighting, right-click and choose copy), and paste it in your next reply with a fresh DSS log.
Close OTMoveIt
If a file or folder cannot be moved immediately you may be asked to reboot the machine to finish the move
process. If you are asked to reboot the machine choose Yes.
After posting both logs see if you are able to reinstall avast! and also test whether or not you can boot to safe mode. Then let me know how that works out.
Also, as David pointed out, running avast! and AVG
AntiVirus is not advisable, but avast! and AVG
AntiSpyware is a very good combination.