A nubie!
Our system was running fine, but then we had a power dip, and the machine stopped before it was able to finish.  The computer went to blue screen.  After restart of Mach3, we noticed our cutter has been cutting to the left, after about 3/4 down our cutting line.  Our dimensions of home position and end position has not changed and is correct, however the cutting is veering off it's line, we have not changed anything in the software set up.

What could be causing this? is there a corruption in the drivers?

Hi drivet,

Welcome to the forum.

Restarting after a 'brown-out' or sudden disconnection of power is risky at the best of times. There is no way to know exactly where the machine came to rest in relation to the GCode line number etc.
Probably the best procedure would be to restart the job completely from the beginning and then cut air until the program caught up with the work that had previously been completed. Even then it is only as good as your work's home / start positioning.

Tweakie.