A seemingly random event happened about two weeks ago. I tried to burn some data onto a disc only to find that both my 'C' drive and external USB drive (the latter housing my CD RW) had vanished. In addition my host controller for the CD-RW has also vanished. I have consulted the device manager and the troubleshooting facility but none of these appears to work. Each time a get a code 31 message. I have even uninstalled both drives and reinstalled but again, without success.