I have tried to replace a CD Drive with a DVD Drive but the Drive is not recognised. I have connected the DVD in place of the CD carefully checking that all cables are properly in. On bootup the busy light comes on but nothing else happens. The CD was secondary master with a CD-RW as slave and this set-up works well.The DVD Drive has been tested on another machine and is perfect. I have tried removing the CD listing in Devise Manager before installing the DVD hoping it would find the new drive on bootup but no good. Put the CD back in again and everything is back to normal.I run WIN ME and have an AMD 800 processor.