They are
<LINK id="_Portals__default_" rel="stylesheet" type="text/css" href="/Portals/_default/default.css"></LINK>
<LINK id="_Portals_0_Skins_WEBPC_DNN3_" rel="stylesheet" type="text/css" href="/Portals/0/Skins/WEBPC_DNN3/skin.css"></LINK>
<LINK id="_Portals_0_Skins_WEBPC_DNN3_t_worxIPskin_css" rel="stylesheet" type="text/css" href="/Portals/0/Skins/WEBPC_DNN3/t-worxIPskin.css"></LINK>
<LINK id="_Portals__default_Containers_t_worxDNNR_TWC3_css" rel="stylesheet" type="text/css" href="/Portals/_default/Containers/t-worxDNNR/TWC3.css"></LINK>
<LINK id="_Portals_0_" rel="stylesheet" type="text/css" href="/Portals/0/portal.css"></LINK>
The Error message is
A critical error has occurred.
Check your provider configuration for errors! Could not find file "C:\Sites\WEBPC_DNN\portals\_default\skins\t-worxdnnr\skin.css".