No, you do not have to download mach3 again. You already have your license so no problem with that. Do you have an icon on your desktop named "Mach3 Loader"? If you do, double click it and you will see the list of all profiles that are located in Mach3 folder (these are .xml files). Select Create Profile and in next step Clone your existing, 3 Axis profile.
Now you can edit that new profile, assuming that you have added additional LPT port, and assign A axis Step and Dir pins to outputs of Port2. In Motor tuning set your 4th motor as needed.
If you have any additional questions, just ask.
Sorry for writing in English, Spanish is not a language that I even understand, I'm using translate services.
What kind of controller do you use? Parallel port or external motion controller? If you use parallel port, you should consider upgrading with additional parallel port which would handle 4th axis. If you have external controller, just create another profile for your 4 axis setup.That is done easy: Start Mach3 loader, from there create New profile.
Licenses blacklisted in Mach3 (found in .062: Schopler Juberian Allison Scanners bassam PAPA FABIO Ivan Todosijevic Sompob Advanced Control Tech (ACT) MaoA~A ¯Ðtonar rebecca crans Vortech CNC Jeff Sandstrom Maksim Amvtonar
Figure out which one you have
As Tweakie wrote, you should buy one. These blacklisted licenses may give you a lot of trouble and broken bits.
There are some blacklisted licenses known to Mach3. Extracted from .062 executable:
Schopler Juberian Allison Scanners bassam PAPA FABIO Ivan Todosijevic Sompob Advanced Control Tech (ACT) MaoA~A ¯Ðtonar rebecca crans Vortech CNC Jeff Sandstrom Maksim Amvtonar
Sorry for unformated text.
These licenses appear to work, but as far as I heard, can produce some quirks:) What the quirks are, I don't know exactly, but as far as I've heard, "tool breakage" in canned drill cycles ... (movement to next hole to be drilled without lifting tool out of already drilled hole.
Did "they" reinstalled Win 7 32-bit or 64-bit? If "they" installed 64-bit version take your money back. Mach3 can not communicate with parallel port under 64-bit OSes.
Mine computer is still "old" one with LPT port and running under Win XP and is only dedicated to CNC. No internet connection but visible on local LAN. Have a spare motherboard (Intel mini-ITX desktop board).