Hi all,
I was able to isolate the "Shell Hardware Detection" service as the cause of my windows 7 home prof version pc flickering. When I would get a drop down box with options in it, the box would disappear before I could click on an option. By a process of elimination of services and booting up I came down to eliminating the problem by isolating the cause with this particular service.
All the system files scanned and showed nothing missing or corrupted. I figured it might be some kind of configuration associated with this service somewhere that needed to be tweaked, but for now, I just disabled the service and the flickering and drop down box problems all stopped.
I started with the configuration with safe mode with networking support. After getting into safe mode, I noted all the services that were started. Then I rebooted and went do msconfig > services and left checked only the services I found with safe mode with networking support. Then I started adding back services and rebooting and checking for the flickering problem. When I turned the service on that resulted in the flickering problem then I turned on all the services and left the "Shell Hardware Detection" service unchecked in the msconfig > services tab. Then I went over to services.msc and disabled that service. This process is relatively simple but it took most of the day to find the culprit.
This process can be used to isolate other services that are not working correctly. I am including all this description so that others might see the solution to the flickering windows applications a fast disappearing drop down box problems which make operating the computer a real pain.