Win10 equivalent to Windows Explorer?

   Looks like I will be migrating to Win10: new computer - Lenovo
ThinkCentre M92p SFF Quad Core i5-3470.

   There is (to me) a nameless crudely similar DEFAULT thinggie that 
fails to work properly xxxxxx REFUSES to work properly and seems that it 
CANNOT work properly.

   1) How do I get rid of that?
   2) How do I add/install a decent Windows Explorer?

        Thanks.

-- 
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus