Windows Installer

Every time I reboot and log into my Windows 2000 PC a Windows Installer message pops up and to end it I have to use the task manager, the cancel doesn’t stop it. I am not installing any apps and no one else should be trying to do it remotely from a another workstation or server. How can I stop this. It is not in the Startup folder. Also, can I found out who is trying to envoke this app on my PC.

Thanks