If you use OpenType fonts with PS outlines (.otf) or PostScript Type 1 fonts, reportedly the latest Windows update is a bit dangerous. Read this before you decide to install!
http://graphics-unleashed.unleash.com/2012/12/windows-update-kb2753842-w...
NOTE: I have not verified this in person, as I don't use Corel or Quark apps. I also don't yet know whether any other major apps may be affected.