1. Use SYSTEM RESTORE to when it worked.
2. Consider you didn't tell any story or history as to what lead up to this issue.
3. http://www.google.com/search?&q=URLMON.DLL
Ignore the "Sponsored" links, but do tell what you have done to fix your issue. What research have you done?
4. http://www.mvps.org/inetexplorer/answers2.htm#urlmon
Follow the steps supplied. Very easy and safe.
Could your post have a minor typo? Explorer is not Internet Explorer and if so, some of my answers may be slightly off target.
In starting up IE, I get a "Explorer has caused an error in URLMON.DLL. Explorer will now close". It seems to affect viewing videos. A little help, please??

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