Ok, the mightyone is the firmware.
I personally have not had to update my firmware, although its not a tough process, but they shipped mine out with a decent version and it works fine. I am from the old school of thinking, if it's not broken, don't fix it. Nearly 2 years on and I have been able to produce some great prints from the stock firmware.
What you need is the specific USB driver for the machine, which is all in the replicator G package, check this page out and follow the guide..
http://replicat.org/installation-windows
Once you have ReplicatorG and Python etc installed (which should all be included in the one installer now) and you can successfully use Replicator G to print something, you can go and download Makerware which is ALOT friendlier to use for the initial learning process, then move onto replicator G where you have alot more control. Or start with Replicator G and do it backwards, up to you really :) I didn't know I could use makerware with my machine, so I was using replicatorG for ages, then I gave Makerware a go and works like a charm.