Gotcha... I am not sure, though, you would be completely starting from scratch. I had previous Windows XP files that have worked fine on the 64 bit 7. I even have a few programs that are still 32 bit that all seem to run with no problem at all. The only difference is that when you have a 64 bit app, it installs it in the Programs (X64) folder and then uses all the 64 bit threads. The 32 bit stuff all gets installed under the Programs(x86) folder so it doesn't even mix any of the threading.
So far, it seems pretty seamless between the two types of apps. It's not dissimilar to when Apple put out the the Tiger OSX and some of the apps were already 64 bit and some were not but it never made a difference on the user end as the user didn't see anything different. The only thing they could have done to make it seem less differentiating was to get all the programs to install in the same place regardless of bit. Whereas Mac was able to have everything install all in the applications folder, Windows chose to separate them based on bit version.
All in all, I really like Windows 7. For a Mac user, it is the closest experience to the Mac that Windows has ever created. And with Parallels desktop, I can even run my native partition virtually and can run Snow Leopard and Window 7 both at the same time. Now, if I only had the money to purchase licenses of all my software for both systems!
