There will not be any .qat file with Word 2010 unless you had an installation of Word 2007 as well. The file is Word.officeUI. They both go in the same folder. That folder is a hidden system folder. On my system, that folder is:
C:\Users\Charles K. Kenyon\AppData\Local\Microsoft\OFFICE

If you modified your QAT, that file will exist. The ribbon modification file is separate and is named Word14.customUI; it will be in the same folder as the Word.officeUI file. This is for modifications to the Ribbon made through the Word 2010 interface. There is no analog file in Word 2007.

The Startup folder will be empty until someone puts something in it. Many programs put templates in this file or otherwise install Add-Ins. Note there may be two different startup folders, both of which work with Word. One is the (optional) one set in Word preferences, the other is in the Office program folders and will be in all caps.

If you did not see my comments in the thread https://www.msofficeforums.com/word/...locations.html you should revisit it.