Upon start, i get "File access denied"

SUGGESTED

When i click the OK, i get "Open an existing database".  When I click existing, I can browse to the data base and when i click that, same result. Other computer on office network works.

I got an error saying "Not able to create temp file.  May be invalid path, network rights limitation, disk or directory full.  I ran disk clean up and now upon start up I get File access denied.  What did I erase?  What can be done?