Before going to a clean install or repair install (which is a sure shot to fix the issue, but the last resort), try this Win7 default iconpack installer
. Read the developer's direction in the page befor installing, but you need not to make any backup, as those are already messed up.
it should fix your issue.
Let us know what happened.
EDIT : if the icon issue is fixed, then we will fix the explorer frame buttons. Let us know if there are any other system elements carrying that themes resources.