Which font does Microsoft use in Windows 7 in the 'Windows starting', 'Welcome', 'Windows shutting down' etc. messages during boot - is it Verdana?

Hi Abi8220, It is Segoe UI in Windows 7.See: New Fonts in Windows 7Thanks.

I want to uninstall all my fonts and put them back as needed. however, I need to know which ones Windows 7 uses and Office - such as OUtlook. Is there anywhere that I can find a list of ones to leave alone?

Hello trudie2119,basically there is not any official list of which are the fonts that are used by the UI or another application. Because different fonts have been used in different generations of UI design, the number of fonts the UI needs is a little bigger than it might have been hypothetically.Anyway, you should not be worried about uninstalling any of these fonts, since they are all system protected and you would get a system error saying that those are system fonts which cannot be deleted.Saludos