Sign Driver on Win2003 32-bit

Question

I signed a driver on Win2003 32-bit, and it can't run on Win2007 x64. I checked the properties, and there is right digit signature information.

I tried to sign on Win2008 x64, and it worked!

Does any one know the reason?

Answer 1

Because a 32-bit driver can't run on 64-bit Windows.

Answer 2

I found that it effected by certificated file. It's only normal on vista+. I'm finding the root cause.