I have a P3 650Mhz machine running on WinXP Pro SP2 and recently changed my old CD drive. I installed my CRX230ED and turned on the machine. During Power On Self Test the drive was detected but when the Windows splash/boot screen came on the computer hanged/stopped-booting. I turned off the computer and disconnected the power cable to the drive and then turned the computer back on. An error message screen appeared and I chose to start Windows normally. After booting up I did a manual installation of the drive through Windows Control Panel and it was successful although the drive was having difficulty reading original installation discs. When I shut down the machine and turn it back on the same hanging/no-boot problem came back. I e-mailed Sony Technical Support and this is what they replied. You need to have the Sony drive set as master of the secondary channel with no other drive connected. Also use the EIDE cable that came with the Sony drive, not one from your system. Then you need to get any BIOS and Motherboard updates from your PC manufacturer and any Windows updates from Microsoft, including the latest Version of Direct X which should be 9.0C. I did set the drive to Master and it was the only one on the Secondary channel. I even tried this drive on my brother's P4 machine and the problem was still the same. Could this be a firmware problem?