Device Gdi16.hdi: Autocad Virtual

: It is a "virtual device" driver used for printing and plotting. It allows AutoCAD to treat Windows-configured system printers as if they were native AutoCAD plotting devices.

GDI16.HDI seems to refer to a specific header or reference file related to GDI in a 16-bit environment. The ".HDI" extension could imply it's related to Help Documentation Interface or could simply denote a specific file format or naming convention used within AutoCAD or related tools. autocad virtual device gdi16.hdi

If "Hardware Acceleration" is still disabled/greyed out, you may need to manually enable it via the Registry Editor. : It is a "virtual device" driver used