ppl. that are afraid of incompatibilities and stuff do not upgrade to 64bit even with owning both licenses ... the companies with high quality products already produced 64 bit drivers sure a lot of stuff will not work on win64 but if you are some to own a 64bit PC you are not going to use the also PCI GPU you brought 5years ago the 64bit migration goes - IMHO - very fast for the big companies I feel no reason to worry about that here and the licensing is also OK a double license would be nice but it would cause lots of confusion and be quite a disadvantage for MS this way it is clear 64 bit or not and since 64/32 is no option ... its a must in near future all licenses will move to 64 over time and there is no reason to switch back .... for now just check wheter you devices have 64 bit support or not and you'll be fine also 64bit drivers are a sign of good support a company not creating 64bit driver is unacceptable 64bit OS or not