[...]
If you know your way around the registry then do a search for entries containing "Mach4.Document".  If they are absent then this feature will not work.

It is my experience that Mach3 will make these registry entries on installation to XP, but for some reason, it does not when installing to Win7.  Others seem to be reporting that they can be missing on XP as well.
[...]

Hi,
I got a similar problem on two WinXP/SP3 computers recently. On both, installation has been executed at an administrator account. I do not have VCarve/Cut2d, but the same seems to occure with SheetCAM and LazyCAM (where the preliminary is the important one, second one only has been installed to check this issue).

Would you please post where this registry modification is described?

Sincerily
Nicolas