Mac and windows

I have detup a pc that just shares 4 folders over the network and that worked on all platforms but now it had decided to not work for mac's...

 

i have tryed going in to the settings and checked Share files and folders using SMB but that did nothing. 

if you know the nswer then it woud be appreciated.

-Mixchew

P.S i dont own the mac's i use the PC's.