Viewing the Property details of MSI and MSP files in the Installer folder could show that they are connected to software currently installed. To see the folder, you will need to select “Show hidden files, folders and drives” and uncheck “Hide protected operating system files” from the Folder Options in Control Panel. Do note that the Windows Installer folder has a hidden and system attribute.

If you check the folder, you will most likely find a lot of MSI and MSP files in there possibly consuming Gigabytes of drive space. Using tools like TreeSize or SpaceSniffer to find what is taking up excess space on your drive might show that the C:\Windsows\Installer folder is one of them. If you have a smaller SSD or your Windows boot partition isn’t that large, you need to watch every Gigabyte that goes onto it or space can fill up pretty quickly. Because prices for larger capacity drives are still quite expensive, many users have smaller capacity drives. Solid State Drives (SATA and NVMe) are fast becoming the norm for many users to place their Windows install onto.