OS: Windows XP SP2 well... my computer is on for many hours... non-stop the HDD i am having problems with is an 80gb BARACUDA SATA HD It's full of TV shows/cartoons and useless stuff... so thats the reason why i labelled it "TV Shows". the issue i am facing is: I start my computer, & whether or not i access the TV Shows HDD, it just disappears from the explorer / my computer drive list after any arbitrary time period. I then restart my PC and there it is again. But then again disappears after a long time. When i go to device manager, the hard disk is not to be found even after scanning for "new hardware". It's like the HDD switches off. My computer is permanently on and the "TV Shows" HDD is seldom used. No background disk usage occurs on it either. I have other SATA HDD's too but none behave in the similar manner. The computer heats up so i have kept the side case open too. After using "Disk Investigator", it reports no problems with any of the HDD's. Although the temperature readings of the HDD are: HDD 1: 35°C HDD 2: 43°C HDD 3: 42°C - - "TV Shows"... the one giving problems which is fine, although they are too hot but it's because the room temperature here is between 20°C - 30°C. What could be wrong? I made sure the cables are fixed properly, changed the SATA data cable, also switched it from SATA port 2 on motherboard to SATA port 3, but only this HDD plays hide n' seek. What can be done in such a case? I'd appreciate your help.