This fixed my error 3 problem (this is for winxp, the folder for vista would be c:\users\\appdata\local\google\update):
open a command prompt, and type in the following (after replacing
with your username):
cd "C:\Documents and Settings\\Local Settings\Application Data\Google\Update\"
Then run:
GoogleUpdate.exe /RegServe
open a command prompt, and type in the following (after replacing
with your username):
cd "C:\Documents and Settings\
Then run:
GoogleUpdate.exe /RegServe