I have an ASUS M3N /quad core desktop PC, It has two HDDs, both SATA. The boot drive is a 1TB Seagate and the other drive is a WD 1TB drive, internal. I also have a WD 500gig Mybook USB. Windows 7 Ultimate completely crashed, I could not boot even into safe mode. Only CMOS was still accessible. I Had a backup image stored on the internal WD drive. So I restored Windows 7 Ultimate using the Win 7 installation disk. This reformatted and restored the boot drive (unfortunately it was an image made MONTHS ago----lost a lot of stuff!). The only problem now is that neither the WD 1TB SATA drive nor the 500 gb Mybook external drive are being mounted and utilized by Windows. They are just not there in Explorer. However, they both show up in CMOS, and in Windows, they are listed in device manager, and also show up in disk management. And it says they are working properly. I have been able to verify that the Mybook drive is still fine, by plugging into a laptop PC. Have not been able to verify that the WD internal drive is still OK, files are still there or not....but surely the files are all still there since it worked fine for restoration form an image. When I run ADD DEVICE, Windows finds nothing. I ran File Checker, it did not find any problem with system files. Something must be wrong with plug and play....but I have tried plugging in my sons' external USB laptop drive into it, and it works perfectly with Windows. Plug and Play is finding these drives, but will not mount them! Any ideas what could be the fix?