HKLM\SYSTEM\CurrentControlSet\Control\Print\Environments\Windows <environment-name>\Drivers\
The Version-<number> subkey contains information about the drivers for a print environment. There is a different number for each version of the printer driver. Version-2 drivers are Windows NT 4.0 drivers; Version-3 drivers are Windows 2000 drivers.
Note
The Version-<number> subkey is a variable representing the subkeys under the Drivers subkey. It does not actually appear in the registry. This variable subkey displays information which is common to the subkeys in the Drivers subkey.