The DriverStore folder (C:\Windows\System32\DriverStore) is used to store the third-party drivers for hardware by Windows. When you manually install a hardware driver, the corresponding driver files will be copied to this folder. When you uninstall this driver, the files should be removed too. However, if you just update a driver, then Windows will keep the old versions of this driver in case you encounter a problem and roll it back in the future. But the problem is that we almost never need to use those old drives.