Computer crash? Power went out during a storm? And you were in the middle of editing a budget spreadsheet and didn't get a chance to save your work? Ugh.
Microsoft Office programs (which include Word, Excel, PowerPoint) are by default set to automatically save an open file every 10 minutes. So when you re-open the program, your file should still have all the changes you have made — except for the last 10 minutes of work. (Your file may retain more recent changes if you manually saved it yourself by pressing Control+S on the keyboard.)
10 minutes between autosaves not good enough for you? Me neither. Here's how to better protect your hard work:
When someone shares a document with you that's in PDF format but you need to edit it, try the free online PDFConverter. It'll convert a PDF to PowerPoint (PPT), Word (DOC) or Excel (XLS), and you don't need to download any software to use it.
Download these convenient one-page cheat sheets for Office 2007, Word, Excel, Office, PowerPoint, and Outlook to reference the next time you need concise reminders of how to do stuff in each of these tools.