are you sure it has file and printer sharing enabled? Thats one way of resolving the issue
If you still cant access it by name but you access it by internal IP you will have to add extra line in your hosts file
Its always located in %windir%/system32/drivers/etc/ open the file with notepad and add the following line: <internal ip of the computer> <computer name>
Ofc do this without the brackets and do this only if you can access it through IP but not through name