Windows Installer Problems

Hello all ,
I have some problems with my windows installer. Each time i want to install something (XP PRO English OS) i get an error: "The windows installer service could not be accessed ..."
Wen i check the service of the installer it is up and running.
Is there anyway to reinstall this service ?
I tried a procedure from the MSKB but it doesn't work.
If anyone could help me out here it would be greatly appreciated.

John

try stopping the service and then restarting it. I know you can re-install it, but I can't for the life of me remeber where I have seen it.