sharing tab is missing

dear all…
i have the following problem in my company i have windows 2003 domain, all users connected to that domain, the problem is that any limited users ” domain users” cant see the sharing tab in the folder properties,only admins can access sharing tab,but company work flow and requirments needs to allow users to share folders,,,

i have tried the following senarios

1- check the server service… it is started and no problem…

2- uncheck the simple file sharing box at the folder options/view

3- check the regestry [classes_root\clisid\{40dd6e20-7c17…..} ] permisions and gave the EVERYONE full controll

but the problem stell the same… sharing tab is not appears on folder properties

any suggestions please