Windows 7 - phantom drive repeatedly connecting/disconnecting

I have an issue where my computer makes the "ba-dum" sound randomly and hangs for a moment, but I haven't connected or disconnected a drive. It seems only to happen when I am moving the mouse. I noticed it for the first time after Norton 360 started telling me I needed to buy more online backup space. I also noticed that the Norton backup drive, which shows up as an "other" folder in my "computer" folder would pop in and out in time with the sound. I called Norton technical support. They were terrible, so I uninstalled Norton. I downloaded a trial of Vipre instead. When I installed Vipre, it said that Norton had not been completely uninstalled. I couldn't find any Norton programs in my program manager, so I installed Vipre anyway. The sound and hangups are happening less frequently, but they still occur. I no longer see a drive popping in and out on my "computer" folder. Can anyone help with this situation?

fogbat, welcome to the Seven Forums.

Norton never really leaves your computer once installed. If you haven't yet try the Norton Removal Tool,

Download and run the Norton Removal Tool to uninstall your Norton product | Norton Support

that should get rid of the remnants that are causing it.

thanks. i have run the norton remover, but the problem is still here. any further thoughts on what might be causing it?

You can try running SFC /SCANNOW Command - System File Checker to see if Norton left some corrupted files behind.

Check all of your USB connected devices for a loose connector, one may be dis/reconnecting itself.