'Everyone' in MS networking are those with an account. Since you don't have a domain or such but just workgroup did you check your accounts on each machine?
It's interesting to cover 'Everyone' versus 'Anyone.' If you want to allow access to 'Anyone' tell the forum how you would do that.
Just bought a new pc with Vista Home Premium. I set up a small workgroup (named WORKGROUP) with new Vista PC and 2 PC's running XP. All computers see each other in the workgroup. I can map drives and folders between the XPs and I can also map to the drives and folders in the XP's from the Vista pc. However, I can not map to drives and folders on the Vista pc from the XP pc's. (Actually I can map to them, but when I try to open them, I get a "drive not accessible" message.) The drives and folders are set to share to "Everyone".
Need help, please.