The ball has stopped spinning!Please help

[anomit]

I have avast! Antivirus 4.5 installed. You all know it starts along with windows and a spinning ball is seen in the system tray. One day it stopped spinning and displayed a red mark on it. On clicking the ball it showed a message RPC Subsytem Error. Since then avast! does not start with Windows and the resident protection has become disabled. I have checked msconfig and services.msc but the entries regarding avast! are all fine. Please help

[saROMan]

Remote Procedure Calls (RPC) is a Important Process for XP....go to Services.msc and see if Services relating RPC are running or Not ..or may be your Installation files for Avast are Corrupt....try reinstalling over Exisiting setup to save the Defination files.....

[anomit]

Yeah, I reinstalled and the problem was solved. And Voila! As soon as Resident Protection started running 4 trojans were detected!!