I have a secondhand Emachines 420 pc which came with a CD R/W drive and a DVD R drive. The DVD drive was damaged and having got it out I eventually got the mobo to recognise the remaining drive by setting the jumper to CS. I have now bought and installed a new Samsung DVDRW, and I am trying to get the pc to recognise both drives, but it can't spot either of them. I have tried jumper settings of CS on both, and the existing CD R/W set to Master and the DVDRW to Slave, but to no avail. Is this machine only able to recognise optical drives made for it or have I missed summat obvious eg I need to change a BIOS setting or something physically on the mobo? There is only one ribbon cable for these drives, with two ends, the lower marked 'slave' and teh upper marked 'master'. Thanks everyone.