I've been developing a DB within Access2010 in the mdb format. I'm trying to convert it to a accdb format. Per the Microsoft instructions, I have the mdb opened, then select save as, make sure the file type is Access2007 and enter a new file name. After doing this, when I open the new file, it shows its in the mdb format. I've tried creating a new accdb file, then importing the objects, but I'm having problems here also.