"boop" - Issue of my own

Everytime I shut down my PC, when Windows gets to the "Logging Off" screen, I get a "boop" noise (the gentle error noise), but cannot see the issue, since the "Logging Off" screen is in the way.

I checked the Event Viewer, and under Application at the time of the shutdown, I have an entry that says:

"Warning:
Windows saved user NEWDELL\Paul registry while an application or service was still using the registry during log off. The memory used by the user's registry has not been freed. The registry will be unloaded when it is no longer in use. "
This is often caused by services running as a user account, try configuring the services to run in either the LocalService or NetworkService account.

It also sometimes has this entry:

"Warning:Windows cannot unload your classes registry file - it is still in use by other applications or services. The file will be unloaded when it is no longer in use."

The problem is, I have no idea when this started. I have noticed it for quite a while, but never looked much farther than Event Viewer.

I have not noticed any other performance issues.

Any idea where to start troubleshooting? You think this is anything to be concerned about?

PK