Hi Jazz

Yes, thank you for that .. ..

I had discovered the problem with 64 bit Win 7 and Mach3 .. ..I've got 32 bit to load on.

The KVM switch is only between the monitor and both computers and I understood only switches the VGA received by the monitor from one PC to the other. Main reason for this is space is a premium so only one monitor needed. The CNC Controller will be connected directly to the parallel port of the computer with nothing to interfere with that.

Ah, I think I see confusion .. I'm not explaining myself too well ! No change there then ..

My plan ..

1. Computer on my desk 64 bit; 4 Gb RAM Win 7, internet; .. loaded with circuit creating software which generates Gcode. Gcode will be stored on 1 Tb discrete MDD.
2. Computer on workbench, in SS industrial cabinet, 32 bit; 4 Gb RAM Win 7 loaded with Mach3 and Autoleveller, no other software, internet available for software update but normally disabled; Gcode imported from MDD to Mach3 for implemetation.
3. KVM VGA switch used to select screen view from one or other computer.

Please do let me know if you think I'm up the cut in a punt !

Thanks

S