Windows default font messed up... but not everywhere
Solution 1:
You've probably uninstalled the ‘MS Sans Serif’ font.
Autoruns's dialog resources are all specified with the property:
FONT 8, "MS Sans Serif"
Instead of one of the more usual UI fonts such as the ‘MS Shell Dlg’ mapping. So without ‘MS Sans Serif’ or any substitute available, Windows falls back to the horrible last-resort default font, ‘System’.
‘MS Sans Serif’ is a bitmap font so even on a standard system Autoruns's windows may not look right as ClearType won't be used, as it would be with the default ‘MS Shell Dlg’ mapping to Tahoma or ‘Microsoft Sans Serif’ (which is a different font to ‘MS Sans Serif’, just to confuse you).
So re-installing the font (file ‘sserife.fon’) should restore the usual behaviour... alternatively you could set a FontSubstitute to map it to another font you do have installed, such as:
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\FontSubstitutes]
"MS Sans Serif"="Tahoma"
Solution 2:
I have problem like described (System font displayed instead of MS Sans serif) on Windows 7 x64 with additional symptoms - Fonts in Control panel displays Arial instead of MS Sans serif. Problem was solved after switching regional settings location and non-Unicode program language forth to English (USA) and back to my original setting (Russian, Russia). I suppose that switching only non-Unicode program language forth and back should be enough.