A pretty good question came across the newsgroups the other day. Someone was asking what are the differences between IE's "medium" and "medium-high" security settings. I did some digging, and found only this on MSDN: About URL security zone templates. No wonder it's difficult to find -- the terminology is different, and the table is organized by URL actions, not by the text in the dialog.
Someone on the IE security team forwarded me a document that had additional details. So here, for your enjoyment, is a chart listing the default settings for each security level. To answer the newsgroup poster, "medium" and "medium-high" aren't the same.
About the formatting: to get it to fit within the width of the blog's text section, I've made some abbreviations.
In a few cases, the table shows a number rather than D or E or P; below the table is a description of each such entry.
At the very bottom of this post I've included the settings from the privacy tab, too.
Note: these settings reflect those for Internet Explorer 7 on Vista SP1. Please see the MDSN link above for differences between IE 6 and IE 7.
.NET Framework
.NET Framework-reliant components
1 = High safety
ActiveX controls and plug-ins
Downloads
Enable .NET Framework setup
Miscellaneous
1 = Prohibit downloads from software update channels 2 = Cache content downloaded from software update channels 3 = Automatically install software updates
Scripting
User authentication
1 = Prompt the user for name and password 2 = Automatic logon only in intranet zone 3 = Automatic logon with current user name and password
Privacy settings (on the "Privacy" tab)