I use both and don't have a problem with either, but that doesn't help you. I assume that you have Roxio's Easy CD Creator? With regard to the buffer underuns, do you have "Buffer Underrun Prevention" checked in the advanced options of Disc Copier? Also, you cannot have Windows Media Player running when using Roxio's disc copier, but if you do, you should receive a message saying that Windows Media Player is running, do you want Roxio to shut it down? To solve your problem, uninstall Roxio's software completely. To copy CD's in Windows Media Player you will need to first copy the source CD to your hard drive, then use the copy to CD function in Windows Media Player All these options are listed in the left hand pane of Windows Media Player. Please let the Forum know how you get on.