This topic seems to be going back and forth between systems. I will answer on the Mitel 3300 but not sure which was the original question on. A 3300 controller uses a standard IDE Fujitsu 80gig drive we purchase them online for about $75. Your best best is to ghost it from a working drive but if you do not have that ability you will need to load the software from scratch which hopefully you have a copy as 9.1 is about 1gig in size.