Solved: is not accessible. You might not have permission

I know this is an old thread, but still, THANK YOU!!!!! I have been searching and searching for a solution to my problem and have tried most of the things you list, to no avail. However, your solution worked great on my new Win 7 64-bit box.

I did not have an Everyone user group, so I had to create one 3a:

When viewing the list of groups, Edit... > Add...
Type "Everyone" (no quotation marks) in the "Enter object names to select" box (the object types are "Users, Groups, or Built-in security principals" and the location is your computer).

Click OK (or Check Names and then OK) then continue with step 5.

I did this with all four drives on the computer and now I can access them from another computer.

(There's probably a way to create the Everyone group "above" the drives but I was so excited to discover this trick that I just did it for all four drives.)