Thank you both for the quick response.
FavOrg is the programme which appears to do the trick. Apparently, when you clear out your Temporary Internet Files it also resets the icons to the Microsoft emblem (blue "e") This programme is meant to preserve them.
By the way it wasn't easy to find a free download site ( although it's supposed to be freeware) PC Magazine want you to pay $19.95 for the privilege!