Core DLL failed to load

I've been trying to open a pdf document for my school work.  Every time I try to open it, I get a pop up box that says that Adobe failed to load its Core DLL.  Adobe has been working just fine on my laptop until the last couple weeks.  I've even tried to download it again to remedy the problem; but not luck.  What can be done to fix this problem?  Adobe is important to my school work.