iertutil.dll

I just get a strange error while clicking explorer icon , it shows err msg " The ordinal 650 could not be located in the dynamic link library iertutil.dll" and i'm not able to use explorer , firefox is working .. Any idea ?

hi guys... recently i had this problem while installing/uninstalling IE7. the file called "iertutil.dll" goes missing from ur windows\system32 folder. and it bans evrything from opening. however downloading the same file and pasting it in the windows/system32 folder solves the problem...