More information is needed.
What operating system is the Lenovo using?
How are you attempting to access or view the files on the My Cloud? Using Windows File Explorer? Using WD My Cloud Desktop? Using MyCloud.com web portal?
Have you tried “mapping” the My Cloud to your computer?
http://support.wdc.com/knowledgebase/answer.aspx?ID=2676
If prompted for a User name and password when accessing the My Cloud using Windows File Explorer (or Mac Finder) are you using a User and password that was created through the My Cloud Dashboard?
Is NetBIOS over TCP/IP enabled on the computer?
If using Windows is the Network configured for Home/Private?
If using Windows 10 see the following link for additional things to check:
http://wdstagingsplit.staged-by-discourse.com/t/compilation-of-windows-10-methods-steps-and-solutions/142576
