My Book Mirro Edition USB

I have Windows Vista SP3 in my computer. The computer does not understand the SETUP CD, instead of text only “UNDEFINED” is shown. Is it an error in the WD setup CD? or do I miss some program? what should I do?

You can try the steps from WD KB # 2693 but the CD version of the software is most likely years out of date.  In that regard, I simply recommend installing the latest version off our downloads page for your drive.