You might have heard about Icon Cache database in Windows, actually this database keeps cache copies of each and every icon and when Windows need to draw an icon it uses this database instead of retrieving from original file, this makes Windows draw icons faster, but sometime this file get corrupted and you might not see all icons in correct manner.
If you too facing some problem with your icon sets like on desktop your icons are not appearing in correct manner then you can try to rebuild your Icon cache database.
To rebuild Icon cache database all you have to do make you sure your hidden files are visible, once hidden files are shown navigate to following directory
Here you will find a IconCache.db file just delete it and reboot your system. You are done and your icons should appear in correct manner.