Heres an option, and may be worth a try. Create a user on both machines, and make sure you set a password. Then try to connect to the PC's by the name (\\computername). Also, disable the guest account by right clicking on My Computer, and going to Manage, and then going into the user setup and such. It may be disabled already. After this is done, give this user account permission to the Share, and also Security (NTFS) permissions. See if that works.