You can add a menu extension to Internet Explorer to do most anything.
To add a menu extension to increase the selected text size by +2:
01. Close all instances of Internet Explorer.
02. Create the following Big2.htm file in you %SystemRoot%\Web folder:
<HTML> <SCRIPT LANGUAGE="JavaScript" defer> var extMenu = external.menuArguments; var getDoc = extMenu.document; var findSeltxt = getDoc.selection; var createRange = findSeltxt.createRange(); createRange.execCommand( "FontSize", 0, "+2" ); </SCRIPT> </HTML>03. Use the Registry Editor to navigate to:
HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\MenuExt.
04. Add a new sub-key named Big2 or Big&2.
05. Add or Edit an unnamed string (REG_SZ) and set it to the expanded path to the Big2.HTM file. If %SystemRoot% is C:\WinNT, set the string to C:\WinNT\Web\Big2.htm. if %SystemRoot% is C:\Windows, set the string to C:\Windows\Web\Big2.htm.
06. Exit the Registry Editor.
07. Log off and log on.
08. Open Internet Explorer and navigate to a Web page.
09. Select a string of text on the Web page.
10. Right-click in the page and press Big2.
NOTE: You could add a Big3, Big4 etc.., changing the corresponding Bign.htm file.