[H] won't log in

[Winterlight]

on my personal LAN I have a mix of win10 win8 and win7 computers. 
They all share the same workgroup. They all have user name and 
password log ins. They all work fine except for a single Thinkpad 
Win10 pro computer = WL trying to connect to my only Windows 8 PRO 
computer with media center= MC. This operates as my media server. The 
windows 8 computer can log into the Thinkpad. The Thinkpad can log 
into any other computer EXCEPT for the windows 8 computer. I have 
created and tried different user names and passwords, I have tried 
logging in as administrator after enabling administrator on the MC 
computer and giving it a password. Nothing works. Anybody know why?