Have you tried a restore to a previous time when the icons worked properly?
I have read of this interesting solution:-
"After trying most of what was recommended (system restore, registry edits, rebuilding iconcache.deb in several ways) none of which worked, I finally got my icons back !!! Go here: http://www.stardock.com/products/iconpackager/ and get the trial version of IconPackager, install it, use it to switch to any icon package, then switch back (if you want to) the standard windows icons."