How to improve the overall performance of Windows 7

The computer has been used for a long time, the system will produce a variety of garbage, some system garbage will occupy the hard disk space, some garbage although occupying the hard disk space is relatively small, even negligible, but they A lot of garbage branches or key values ​​are generated in the registry, which reduces the overall performance of the system.
In order to better explain this problem with you, first of all, please take a look at the screenshot below:

Screenshot of right click menu
The picture above is a Windows 7 system right-click menu Screenshot, the left side is the right-click menu of the "Death of Death" file in AVI format, and the right side is the mail menu of the "Death of Death" file in RMVB format. A comparison can be seen, in the right-click menu list, there are two players associated with this file format, only one on the right.
In Windwos 7, the right-click menu above shows the "open mode", how many playlists there are, how many plays in your system (including uninstalled after installation). Now we are only looking at the right-click menu of a file format. Let's think about it. Is there a lot of file formats in your system, and there are different programs associated with it? There are many that have been uninstalled. document.
So, where are the right-click shortcuts for these files stored? How can I clean them? Let's take a look at the opening method of the AVI file format as an example to share the origin of the problem.
Run the Windows 7 registry, and then navigate to HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionExplorerFileExts.aviOpenWithList. In the right window, you can see which programs are associated with the current AVI format.

Programs associated with AVI format files
As can be seen from the figure, the files in the AVI format of the author system are respectively associated with Thunder, Storm, and WMP. If I want to remove one of them, "Open the way", delete the corresponding key value directly.
Edit Comment:
In the above situation, how much the right file is opened will directly affect the size of the Windows 7 registry, and the size of the registry file will directly affect the overall performance of the system. What I have listed is just a file format. For other more redundant key values, the user can expand separately and then one by one.