title: Converting Windows driver to 64 bit - can I use a 32-bit DLL?
body: <p>My Windows driver has a .sys file and a .dll (which I'm guessing is the programming interface to the driver?). Anyway, I need to compile the driver to run on Windows 7 64-bit. I have downloaded the <a href="http://en.wikipedia.org/wiki/Windows_Driver_Kit" rel="nofollow noreferrer">DDK</a> and am able to compile everything, but my application still won't work with the new driver.  </p>
  
  <p>If the application is a 32-bit application, does the driver DLL need to be compiled as a 32-bit DLL, and the .sys file a 64-bit file? Or do the SYS and DLL files both need to be 64-bit?</p>