Thanks to everyone who responded. I have been doing some further troubleshooting and found the freeze up seems hardware related. I have an Asus M5A99 mobo which has 6 SATA III ports and 2 SATA II, so of course I connected my 5 hard drives to the SATA III ports and the 2 optical drives to the SATA II ports. I have tried the optical drives 1 at a time on the SATA II ports, also tried different cables, but until this weekend I had not tried the optical drives on the SATA III ports. Of course they work perfectly now and I can play music CDs without a problem.<br><br>I don't know if this means that the SATA II ports are faulty or if Windows 8.1 drivers for the chipset are faulty, that is a question for ASUS to figure out.<br><br>One piece of weirdness that has come u is that the mobo tries to boot off my ASUS&nbsp; BD drive no matter what I do (short of disconnecting the drive). I have my C: drive set as the boot drive. I have tried F8 to call up the boot menu and selecting my boot drive from there. Either way I get the "Please insert boot media..." message. Once I insert the WIndows 8.1 boot disc, I get press any key to boot of the CD/DVD. If I ignore that a few seconds later the PC boots off my regular boot drive (an SSD) and I am in Windows seconds later. That will be another problem for ASUS support to figure out.<br><br>Thanks again for all your responses.<br><br>