I wouldn't mess with msconfig. That's a temporary fix and I believe that will give you a new popup anyway. Something like " msconfig has detected...blah blah"

Just go turn off the service if you are familiar with what is running on your pc. Deleting the registry entry is dangerous if you don't know what you are doing but it's quite easy if you do. However, I have my entire PC backed up so I don't sweat it.

Go to Control Panel/administrative Tools/Services and see if you can find the service that is bothering you. Disable it. Hell, you could probably go trial and error. Whatever you do, don't disable RPC or Remote Procedure Call.

If it is a pop-up bothering you, you probably just need to turn off your Messenger Service or your Help and Support Service. I would turn off just about anything that says that it delivers pop-up messages to your desktop.