No Title Bar, no tab visible sheets, all shows in backstage Print; not hidden.

I was working on a class project last night. Had a work book open, opened another and then closed/saved the previous. Renamed and saved the new one. Worked on it a bit and closed it; went to re-open the new workbook and there were no tab sheets that were previously there, because I had saved work in one of them. I went to File > Print and was able to see both pages.

I Googled my problem, found a hidden and very hidden, tried those but un-hide is not available, and un-hide really hidden is set to un-hide. Now each of my student data files that I open for future work, show up the same, i.e. no tabs or Title bar, etc.

I don't recall tapping any strange keys that gave me a new, unfamiliar screen; everything was fine, and I don't think opening the new workbook before closing/saving the previous would cause this major problem of everything going out of whack.

Please help, my assignments are due Sunday June 24. I was up until 6 a.m. ET trying to figure this out, then it hit me-- I remembered I had joined this forum...

Teakie

OK, I finally found the answer in Microsoft Answers:
Right-click on the right edge of the worksheet as if you were going to re-size, fill the Tiled dial, check Windows of active workbook. <OK>
Worked for me!