Can a 32 bit User-mode driver run on top of a 64 bit OS?

Question

I have been checking out some info about 64-bit driver development; I found that drivers have to be re-written in order to be compatible with a 64 bit OS. However, I was wondering if this also holds true for User-mode drivers.

The reason that I am asking this is because my understanding is that user mode drivers pass through the Win32 API, so in theory they should be able to run on top of WOW32.

Is this true?

Thanks, Jaime

Answer 1

User mode drivers can be either 32 or 64 bit, but note the following:

User-mode drivers must be 64 bit for print, scan, and camera. Legacy APIs (that are specific to Windows NT® 4.0) are not allowed.

http://www.microsoft.com/whdc/driver/kernel/64bit_chklist.mspx