Operating system doesn't matter as long as it's Windows 95 thru XP or DOS. This is the firmware V2.0 for updating the CW-7501. There are no other updates for this model. This update is to help solve the buffer underrun errors common to the early firmware drives. Be sure to make a bare boot disk on floppy first, then use the disk to boot machine with. Unzip this file to the boot floppy and run the program from dos.... do not attempt to run it while Windows is running.