In a printer configuration on the "Identification" tab the application "splwow64.exe" is displayed as the the application you've printed from and the option cannot be enabled.
This happens only if you print on a 64-Bit operating system using a 32-Bit application. 32-bit applications cannot use 64-bit binaries. The "splwow64.exe" is a 64-bit application, therefore able to speak with 64-bit printing drivers and "translates" the communication between 32-bit applications and 64-bit drivers.
Identify the document using a text string.