Picked up a Sony DRU 500 AX. Running XP home, Pentium3, 933, 384 ram,100 gig Western Digital. Removed old DVD,CD Rom drive(a slave). I could have left it in, but I have a Plextor,40,12,40 CDRW drive in the other bay and wanted to keep it for awhile. Put jumpers on 500ax to slave and installed it. Windows XP picked it up right away. It identified it as a DVD-RW drive and gave it a letter, and it also gave a different letter to the CDRW portion of the drive. I DID NOT INSTALL ANY SONY SOFTWARE!!( after reading all the posts!) I had downloaded the newest version of DVD X copy, 1.5.2. I had called 321 and we did it over the phone. The sales person assured me that I could upgrade to Express( which will shrink a movie to fit on one disc or Platinum when it comes out, at no extra charge). I used a Sony CD+RW, A TDK-R, and a Sony +R, to copy a new instructional golf DVD that I own. It came out perfect on all 3 copies. Since I have only one DVD drive in use now, the DVD X copy rips to the hard drive. During ripping, the cpu only ran around 5-7%. During the burn phase, it ran at 12-15%. The buffer indicator on the DVD X copy screen stayed around 96% full most of the burn.I use WIN DVD to read the program on my computer.The +R,the -R and the +RW copies played perfectly on my computer.The +R and -R played perfectly on a Sony s550d, and a Sony, NS 400 D. The +RW did not play on the Sony or Denon DVDs. None of the discs played on my Denon progressive scan 2800 2. The Denon manual says that none of these kind of discs can be played. Believe them. The burn and rip rate were around 2X, the capacity of the discs. The DVD ROM drive I removed( a Pioneer from Gateway) does rip faster than the Sony. I believe that if I reinstall the original DVD drive and move the 500 ax to the other drive the faster DVD drive will prevent any buffer underrun errors. Not sure what firmware came with the Sony 500 ax. Anyone know how to find that feature? Thanks for all the posts, it helped me avoid the errors with the Sony software.