Try this at your own risk:
Go to Start > Run, and type Regedit.
navigate to HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\StuckRects2
and delete the Setting entry
Also this location as well:
HKEY_USERS\S-1-5-21-4061621919-1254611917-3314822544-1000\Software\Microsoft\Windows\CurrentVersion\Explorer\StuckRects2
the S-1-5-21 SID is unique for every user. Substitute the one above for your user account.
If this doesn't work, try starting in Safe Mode, then restart normally.
Also, look over the threads at the bottom of this page relating to the icons.