Windows 7 Search Not Working?

So, I've been trouble free on Windows 7 for a long time. Today, while searching for a document containing the word "audit" I realized that my Windows 7 search is not returning correct results.I open up the Documents library link, and I see all of my files. I see files with the name audit in them. I go to the top and put audit into the search field and it comes back with 2 files...and misses handfuls of other files that contain the word. I then search for .xlsx (as this is a spreadsheet) and I cannot find that either. I can find other .xlsx files, but not a good handful of them.I've cleared the index and rebuilt it, but that didn't resolve the issue. My results are the same as they always were.