Sometimes in Windows 7 file explorer freezes upon right-clicking a file or folder. I understand this is a 3rd party software fault. Is this really so?
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This could be any number of issues including third-party software. You need to provide more information on your environment or what you are trying to do when these freezes happen. eg. are you connected to an active directory domain?
The culprits in my experience tend to be:
Network operations are unpredictable and can "block" the system from processing the UI hence the freezing. Are you connected to a domain? Do you have a lot of file shares mapped or open? Sometimes drives can go to sleep and Windows will make a request to them when you access the context menu which triggers a number of actions behind the scenes which block the system.
Shell extensions are things like Tortoise SVN that add additional options to the right-click (context) menu. If these need to do additional processing to show you information (or there is a bug) then there is a chance that the processing will block and prevent the shell extension from displaying immediately.
(This is not a programming site but it helps to understand that Windows applications have a thing called a message pump. If you the messages are not being pumped frequently the result is a freeze, or other unpredictable behaviour. You may not see any CPU usage in Task Manager either!)