You have to enable some settings for unregistered users. AdminCP - Usergoups - usergroup Manager - unregistered users - Forum Viewing Permissions -Yes
They can see my forum already i just want them to download or see my attachments. Is there any security problems with that?
You have to enable some settings for unregistered users. AdminCP - Usergoups - usergroup Manager - unregistered users - Can view attachements
If you have a busy forum I would advise on holding down your thought of showing attachments to guests, it will get you un-necessary loads.