Going crazy..exception and cannot find file

Dear all, I had hoped to add to a program this weekend. I used my external harddrive to bring my files home to work at home. I am getting this message about my file being in the project directory tree as well as an exception from HRESULT:0x800A03EC

I am so frustrated. I have sat in a chair all day trying to figure this out. New to programming. I am 51 and trying to get back into engineering after 16 years of being out of it. Please help me.