Well my old WinXP has eventually died so I had little option than to upgrade to something with a little more acumen and even though W7 is also obsolete it is fast enough for my needs.

The problem I'm having is that as soon as I have installed Mach3 ver 3.043 and opened it up it causes a system error and reboots the PC.

I'm thinking it could perhaps be the Parallel port driver. I'm still waiting for the new LPT Card to arrive by Royal Snail so at the minute it doesn't have one.   

Any ideas anyone?

Cannot run 64bits windows 7 if you want to use parallel port.