Hi,
this is a frequently asked question. Have a look at the threads in the 'Mach under Vista' section of the forum, there are lots of posts
about it.
The upshot is that 64 bit architecture precludes drivers of the type necessary for Machs parallel port, that can only be accomplished with
a 32 bit architecture.
The good news is that XP and Win7 32bit both do a good job of running PP if you wish. If you really want 64 bit then use an external
motion controller which can be had for as little as $100.
I have run Mach3 with 32 bit PP, Mach4 with both 32 and 64 bit OS with an ESS. I think the ESS is great but 32/64 makes NO difference
to how Mach runs. If you want 64 bit its NOT because Mach runs better its because you WANT some other program that does need it and
really shouldn't even be installed on a machine control platform.
I have installed the barest minimum software on my machine control platform because I've had personal, expensive and painful experience
of what happens when some other program or process starts or runs while you are machining, Mach loses the plot and CRASH!
Craig