Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
First, I want to check: is all the data lost off the hard disk on your computer?
If not, by all means, copy it off if you can - it might be necessary to wipe the whole hard disk completely, and in any case your data is at risk.
As to any message about
that by its look would reference an error message from some routine run from a CD or DVD drive/disc. The 'X' is used because
A. the error message is hard-written on the CD
B. and so it is invariant despite the routine being run could be run from a great many different 'drive letters' - so 'X' instead of 'D:' or 'E:' etc.
Perhaps such an error appears owing to your running the routine from the 'wrong' (speaking loosely) drive letter.
But unless that error message stops the process dead, I wouldn't worry too much about it... but that's the question: is the disc routine stopped by that 'cannot find' error ?