Nero is the program that comes with some hard drives and video cards. It is bloatware containing far more than just the drivers for your media. The problem is that some of its functions do not turn off when you tell it not to run.
Even if Nero is not running on your machine, something like it could be... Windows itself has an indexing function that can be turned off and on.
Opening the task manager on your machine will show you everything that is running in the background. I found at least 5 programs that I did not need running automatically on my new computer.