RUN A DLL AS AN APP error message?

Today I encountered a problem that won't go away. Whenever I try to open "My pictures" to change my desktop background, or to move pictures around.... the second the window pops up, I get an error message that says "Run a DLL as an App has encountered a problem and needs to close, we are sorry for the inconvenience." When I try to debug it does nothing, so I have no choice but to close. I've never had this problem before...and have absolutely no idea why it started, or how to fix it. I'm not that computer savvy, and I need help. please.