Rojo,
First unplug the printer from PC. Next go to Start/Settings/Control Panel/System/Device Manager...Scroll down to USB, highlight and delete everything in there. Restart computer and let fully boot up (you will see a few prompts...found new hardware...that will be your on board card reader, etc...just yes through it if it doesn't do it without your intervention). After completely booted up, plug in your printer and your computer will find it and try to install the drivers, if windows cannot find the drivers then put in the Mimaki disk and browse to the driver folder (now keep in mind if your new computer is 64 bit and the disk only has drivers for 32 bit, the disk is no good and you will have to contact Mimaki for 64 bit, if even available). This will not be your software because your software recognizes what printers are installed on your PC and goes from there, if not installed correctly the software is moot, because it looks at your system for printers installed wither it is local or over a network, via the IP. If that does not work for you fell free to call me tomorrow, 563.529.6167 I will be more than happy to walk you through this, this is a pretty easy fix.
Terry