On my home computer running Windows 7 x64 and Office 2010 x64 I've got a weird issue where my default font seems to have been changed / increased without me doing it. I've reset the default fonts on the system and it doesn't have any effect.
Here is a screen shot from Outlook 2010:
The font size appears to be blown up / larger than normal. In Chrome (I haven't taken a screen shot) the rendered font isn't blown up like in Outlook instead it seems to be a different font entirely.
I found this somewhat similiar issue: Outlook 2007 font sizes only they method used to resolve it (permissions on the font folder) for this question doesn't seem to work for Windows 7.
This problem appears in other applications like VMware Workstation, Chrome which makes me thing its related to Windows and maybe a permissions problem with the font.
Any ideas? - know which fonts these use?