Hi Hasan,

The .MSP files are used by the Windows Installer service to cache installer data files for
various applications.

Although the directory with these files will keep growing in size and cause space constraints, we do not recommend removing or deleting them.

This is essentially because installed applications may need these files to allow you to reinstall them at a later stage or repair them. There is a reason why these are hidden in the Windows folder.

If you are willing to risk the inability to reinstall applications, then you can use tools like Windows Installer CleanUp Utility or Windows Installer UnUsed Files Cleanup Tool to remove these .MSP files.

Hope this helps.

James