If you use Eudora Mail client, there is a “bug” in Eudora that automatically sets the default font size in Windows Internet Explorer to small. According to a posting on a Google group, there are two solutions, but it may be that you have to do both of them.
Eudora messes with IE’s default font size setting by changing its registry entry. Therefore, it can also be reversed by reversing this change in the registry itself. This is done through a Windows system program called “regedit”. To change the registry entry do the following:
Go to the Start Menu and choose the “run …” option in the bottom right corner of that menu.
In the resulting dialog box, type in “regedit” after Open and click OK.
A window will appear with a hierachy of folders on the left and a list on the right. It will show the folders in “Software” In the folder tree, navigate to the following folder: SoftwareMicrosoftInternet ExplorerInternationalScripts3.
Upon opening folder “3”, you will see a list of choiced on the right.
Choose “IE Font Size”.
Under the Edit menu, choose Modify
It should show “0000 01 00 00 00”. The first four zeros are un-editable, but you can and should change the 01 to 02.