Windows XP Adding new hardware issue in XP

I've been experiencing "double and triple click" issues with my mouse and am trying to replace it with another mouse. When I click on "Add Hardware" in the control panel I get an error message that the wizard is already in use installing a new hardware item and two items cannot be installed at the same time. Retry after the wizard concludes. It has not concluded in a week now. I have not tried installing any new hardware in over a year (that was a camera that also gave the same message). How do I shut off the install hardware wizard? I find NO CONFLICTS within the device manager to resolve???? Any assistance would be appreciated as I would love to install the new mouse and also the camera.