1. The owner used a registry cleaner.
2. There is or was a malware/other infection.
Curing this can be as much work as Grif notes at http://forums.cnet.com/7726-6122_102-5509131.html?tag=posts;msg5509131 to undoing the damage with System Restore to go back to when it worked.
Bob
PS. Yes there can be more causes but these 2 repeat and repeat.
How to get rid of "You are attempting to open a file type 'application extension .dll" it pops up until my PC shuts down.. it happens every time I open my PC..

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