A lot of those could cause the problem, disable all the ones from the Context Menu category that don't have 'Windows Shell Common DLL' in their description, then kill all explorer.exe instances via Task Manager, then File -> Run -> explorer.exe, and see if the problem is solved. If it is solved, you can try enabling some of them back, and pinpoint the exact one which causes the problem. If the problem was not solved, Try disabling the Browser Helper Objects (especially the McAfee/SnagIt ones I see there). If even this doesn't solve the problem, disable all that are not made by Microsoft.