How to change font size in a fixed-font chm file

Sometimes the font size of a chm file is fixed. To change the font size, go to IE and select Tools>>Internet Options. In the General tab, click the Accessibility button, and then check the “Ignore font sizes…” option. You even can apply your own css style file there.

Adjust the font size:
1. change the font size in IE or
2. directory change the IE font size settings in the registry:

[HKEY_CURRENT_USERSoftwareMicrosoftInternet ExplorerInternationalScripts3]
the first two bytes can be 00, 01, 02, 03 and 04 from the smallest to the largest.