I have a 250gb Maxtor external hard drive which uses USB 2.0 (and firewire). I copied the complete curious labs, poser 4, runtime folder onto it and then made a shortcut to the poser4.exe file and put it on my desktop. I did run Correct Reference, available in freestuff, and it seems to work fine. I use this for "experimentation" and keep poser on my C: drive for Sunday Best.