So I followed all the advices and voodoo tricks on the thread that did not lead anywhere and found another one that finally fixed it.
My specs and situation: Windows 7 Home Premium cannot access the shared folders on any computer on my home network (same workgroup) especially not the ones off my NAS. Tried sync’ing the clocks, disabling IPv6, removing the 4to6 network adaptors (I had none), messing with secpol.msc (not available on W7 Home), the firewall is off, sharing is allowed and so on…
Finally what fixed it was re-enabling the “Client for Microsoft Networks” in the network adapter settings:
– go to Network Connections, right click the one you use -> “Properties”
– “Install” -> “Client” -> “Add”
click “Microsoft”, click OK, reboot and my shared folders appeared!!