Using Win7 and Mach3 version R3.043.066
Problem: stated in subject line

All was working last year, but have not used it since then

Check your wiring.

In particular the X axis Direction pin connection.
If you are using the Parallel Port then check your 25 way cable itself.
Also check the wiring and connections to the X axis motor (check both windings are connected).

Tweakie.

Thanks for your reply.
I have checked the  Dir connections, and all are OK.

Steppers are NEMA 12v 2 phase 1.8 ° 4 lead    Resistance/Phase 1.5 ohm

Checked, with an ohmmeter, the the readings, at the X motor, are:   A - 2.0, B - 2.2
   Y motors A - 1.4, B - 1.6   Z motors A - 1.6. B = 1.4

I will check further, when I have time, and let you know what I find

Don