The latest version of the avast! removal tool doesn’t need you to boot to safe mode before you run it.
You do need to allow the tool to reboot into safe mode to do it’s job. Once the removal has been completed. your system will again
boot into regular mode.

http://www.screencast-o-matic.com/screenshots/u/Lh/1369570130732-96839.png

Simply select YES to start the process.