I see numerous CD/DVD threads here and mine is similar but somewhat different from any of the others, so I will start an additional thread. I have a home built computer with a Biostar 945GZ Micro 775 Motherboard (Intel 945GZ an ICH7/R chipset), Pentium D 830 3GHz Processor, 2 GB ram, 250 GB SATA harddrive, HP dvd 1040i DVD-RW, and a recently added Lite-on HDP118 dvd rom drive (both DVD drives are IDE drives), running Windows 7 Ultimate that was installed on a fresh formatted harddrive shortly after Oct 22 last year. (This is not an upgrade from anything, just a fresh install on a formatted and clean drive.) The HP drive has been the only DVD drive on the machine until I decided to install the second drive only a few weeks ago.. The problem started with the Lite-On DVD drive installation. Winows 7 will not recognize the second drive. I have tried every possible jumper setting and CS ribbons and non-CS ribbons (CS=cable select). I can make the Lite-on DVD-ROM work or I can make the HP DVD-RW work, but no combination will make both of them work at the same time. Since the new DVD-ROM works when it is installed at the end of the cable as master, I know it works. I also know that the HP drive works. I have tried about 6 different cables, at least one of them being brand new. When I boot the computer, the light on both drives blink, and the light blinks for a couple of seconds when a CD is inserted in either drive. But the second drive (slave) is not recognized in Winows Explorer and does not work at all. There is no drive letter in Windows Explorer for the slave drive. These two DVD drives are on the same Motherboard IDE header and are the only devices on that header. I have read about numerous problems that numerous people are having with CD and DVD drives in Windows 7, but none of these exact symptoms. I have not read of numerous solutions to these numerous problems, tho. I'm just wondering if anybody knows of a registry tweak, or a BIOS selection or something to make Winows 7 recognize multiple DVD drives?