This drive works fine, immediately recognized under W8.1. Personally I do not use the automatic backup program because this disc is intended to have all my data and my movies on my laptop with me (I have a NAS for backups with my IMAC) It may be important to note that the above are copied mkv movies played on the Freebox player by connecting with the USB plug. I have copied 1.5 TO movies from another usb3 DD 3.5 "by connecting directly to the NAS (Imac still USB2) and the operation lasted about 6 hours without any problems. The Western Digital is silent and only heats no, the codon 40 cm which is sufficient for conventional bonds. Attention to the thickness of 21 mm for the purchase of a hard case ... you have a little forced to put the cable in the "Port Designs Colorarado" I bought at the same time. I recommend this purchase comes as expected with Premium. Packaging impeccable as usual