I have accidently dropped my 500 GB Western Digital SATA hard drive when moving it to other computer. I used that hard drive as secondary hard drive. After reconnect the hard drive to my pc it's still look normal. I can access the file. But some files appears to be corrupted. I check it with some hdd utilities and it's got some bad sector but still accessible. But today when i start my pc, it's totally undetected. It's not appears in windows nor the BIOS. I've tried to check the cable, change the cable, put it on another pc, but it's still missing. What should I do?