The specified path is invalid

I get this message when ever I try to open any shares through the network neighbourhood
for a particular computer example computer name is singh and I want to access a shared folder called service pack 6a. It would say
that:-

\\singh\service pack 6a is not accessible
The specified path is invalid.

I checked the permission for the share and everyone has full control so does that administrator.

What could be wrong any ideas.

Thanks