I am running Windows 7 and would like to use My Cloud 4TB as both a backup for 2+ computers, and as a shared drive for pictures, videos, and music. I need help properly configuring this setup. Thanks in advance.
Have you read the My Cloud User Manual (https://support.wdc.com/product.aspx?ID=904)? If not you should do so. It explains in general terms how to use the various features/options of the My Cloud. For Windows there is the WD Smartware program for backing up content on the computer. For Apple/Macintosh there is the Apple Time Machine. There are any number of paid and free third party programs one can use to backup a computer to the My Cloud or similar network attached storage device (NAS). There is also WD Sync but a sync performs a different function as compared to a backup.
Various WD software for the My Cloud can be downloaded at this link:
https://support.wdc.com/product.aspx?ID=904#WD_downloads
One can read the WD Smartware User Manual at this link: http://support.wdc.com/knowledgebase/answer.aspx?ID=15136
