Another way to fix the problem, just add the path to ashDisp.exe into
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
(as the value named avast!).
Are you by any chance using spysweeper?
If so, use the restore/recover or whatever it may be called to restore the deleted registry entry and update your definitions file for spysweeper. It reports incorrectly (false positive) the avast ashDisp.exe which is the icon you see on your system tray.
Other programs that can block are the startup monitors: PrevX, ProcessGuard, WinPatrol, TeaTimer, Ad-watch, etc.
Do you have any other antivirus in your computer?
