Learning about 64-bit driver issues caused me to...
Thomas Divine: ...think about "Which came first - the chicken or the egg?"
I brought up my first 64-but Windows system in December, 2003 using the Windows XP 64-Bit Edition for 64-Bit Extended Systems Customer Preview Program. The install went very smoothly, and the new OS just had a "good feel" about it.
I was lucky because the vendor of my AMD64 desktop had the foresight to make sure that there were 64-bit drivers for all of the hardware components on that box. They wouldn't even admit that the box was capable of running 64-bit Windows XP (because it wasn't released...), but they knew what they were doing.
I first wrote about 64-bit driver issues almost exactly one year ago in the article "Extending The Microsoft PassThru NDIS Intermediate Driver--Part 3 Supporting Windows XP 64-Bit Edition" on the Windows Driver Developer's Digest. The article can be found at: http://www.wd-3.com/031504/PTEx3_index.htm 
I found that it was fairly easy to adapt most of my NDIS drivers to 64-bit.
However, I also found that migrating to 64-bit is a "chicken and egg" situation. I had my 64-bit drivers (the "egg"), but no 64-bit applications.(the "chicken").
Sure, I could build a few fairly simple 64-bit test applications using the 64-bit DDK tools - but I couldn't build 64-bit versions of my MFC and .NET applications. (I can now using Visual Studio .NET Whidbey - but that doesn't count because applications built with these Beta tools can't be shipped.).
So, I elected to go a little further and adapt my 64-bit driver to support both 32-bit and 64-bit applications. This took a little extra work, but taking this extra step seems worthwhile until VS 2005 is finally released.
Thomas F. Divine
http://www.pcausa.com
