When you install the NVIDIA display drivers (including other driver add-on software, such as 3DVision, NView, etc.), the NVIDIA Installer first creates a cache location on the local drive, copies the contents to that location, then performs the installation using those files.
The cache location created is the <systemdrive>:\Program Files\NVIDIA Corporation\Installer2 folder. The native Program Files location is used regardless of the package type; that is, Program Files (instead of Program File x86) is used even if the Installer and the software installed are 32-bit.
Each time a new package is installed, the Installer adds the package contents to the Installer2 folder.
Why is the Installer2 folder needed?
The Installer places all driver and related add-on software in the Installer2 folder to ensure that re-installs and uninstalls are successful and complete. The original installation media - whether a downloaded self-extracting executable, a CD, or network drive - does not need to be present as long as the files are stored in the Installer2 folder. This allows device or OS-initiated driver installs (such as a driver rollback) to successfully install the corresponding add-on software that would otherwise be unavailable if the original install media was not present. Without this cache, only the driver would be installed. If add-on software was already installed and running, then there would likely be a version mismatch between the newly installed driver and the add-on software.
I did not install any driver add-on software, yet I still see the software files in the Installer2 folder.
During a Custom Install, even though you might choose to not install a particular software add-on, the associated software files are still stored in the Installer2 folder. This is so the software can be installed if required during a rollback or other OS-initiated driver install.
How can I reduce the size of the Installer2 folder?
There are 2 simple ways to achieve this:
Method 1: Always uninstall the driver and other add-ons before installing a new driver.
Just uninstalling the add-ons, such as 3DVision, will not remove the corresponding package from the Installer2 folder. This is because the associated driver itself still exists in the driver store and could be reused. In this case, the software files are needed in case they are reinstalled.
Uninstalling the driver removes the driver from the driver store as well as from existing devices using it. Once the driver is removed from the driver store, the add-on files in the Installer2 folder are removed as well since the Installer will see nothing that could demand their use.
Method 2: Select "Custom Install" and select the "Perform Clean Install" check-box.
A "clean install" deletes the currently installed NVIDIA drivers as well as cached packages first and then installs the newer driver.
Note: Performing a "Clean Install" will not save the previous driver set.
Note: Performing "Express Install" does not clear the Installer2 folder.
I've uninstalled the current drivers from my system, but files remain in the Installer2 folder.
It is likely that you still have other NVIDIA drivers in the OS driver store. In this case, the matching files for the driver and add-ons are preserved in case the driver is reinstalled from the driver store.
I've performed a "clean install" and then uninstalled the drivers from my system, but files remain in the Installer2 folder.
It is likely that you have performed some combination of multiple install/over-install/uninstall cycles and files from older drivers are left in the folder. The "clean install" removes only the current driver files before installing the new driver. In this case, the simplest way to remove the files is to delete the Installer2 folder.
What happens if I delete the Installer2 folder when NVIDIA drivers and software are still installed on the system?
Deletion of the Installer2 folder will not affect any of your currently installed NVIDIA drivers or software. At most, it will prevent complete installs from occurring in the case of using an older driver from the OS driver store.