Accessing files hares

I have 5 vista PCs in my house and the problem that I am having is that only
one of them has the ability to be accessed by other computers. In other
words, The Office pc is sharing some folders and a printer and all the other
computers can access it without issue (this was upgrade install). The other
computers(clean installs) on the network also have folders being shared and
when I browse for them through the network window the shares themselves are
visible, but when I try to access the file share it gives me an error message
saying that 'you do not have access to this network resource'. i have
password protected sharing turned off, the windows firewall is turned off and
i even set the computers on the network to manual IP addressing. One other
note, when i fist set up the computer (fresh install) the file shares are
accessible on all the other computers, but after 2-3 weeks it breaks and i am
unable to make it work after that. i have also tried creating new shares and
that doesn't work either.

Thanks,
-Fredo