system
1
When I got home from vacation, the system tray icon was missing. Nobody have been tampering with my puter, so I dont understand it.
I can still startup the avast Splash screen by pushing my desktop shortcut-icon, here I updated the software but the icon in system tray is still missing.
I have the 0402-6 version.
These processes are running on my Win 2k OS:
ashServ.exe
ashUpdSv.exe
As I recall, there used to be one or two more processes from avast running. Now theres not.
RejZoR
2
You need to run ashDisp.exe
(you should also run ashMaiSv.exe)
Or try my tweak tool which does this automatically 
http://forum.avast.com/index.php?board=1;action=display;threadid=3021