I installed a second hard drive in my Dell Dimension 310. The hard drive is a WD 500gb sata2. I put it in connected the cables.....all ok. I powered up the computer. Machine doesn't recognize the new HD. So, I took it out and put in primary drive space, and formated it and runs fine as primary. Anyone have any ideas as to why this is happening? I know the hard drive is working. Also, I checked the bios and it didn't show up there either, nor in device manager.andrewdesposito@optonline.net