IE7 Runs with Lower Privileges Than Notepad

Internet Explorer 7 runs with lower privileges than Notepad in Windows Vista. A common scenario where this detail becomes evident is when you attempt to view the source code of a web page, but only from Windows Vista. If you choose View and then Source or simply right click and then from the contextual menu select View Source, Internet Explorer 7 will prompt you with a warning.

"Internet Explorer Security: A website wants to open web content using this program on your computer," is the message displayed and if you read on you will see that it is associated with opening Notepad to enable you to view the source code. The security alert also reveals the reason for the prompt: Protect Mode.

"Protected Mode runs the IE process with lower privileges and also helps protect against malicious webpages that try to automatically pass content to higher privileged applications like Notepad. Before launching applications like Notepad that weren't designed to work with low privilege, Protected Mode displays a prompt to get your permission. This prompt is designed for the worst case security scenario, which is a malicious webpage trying to silently elevate out of Protected Mode by launching an application or reusing one that you're launching," explained Marc Silbey, Microsoft Program Manager.

This restriction acts preemptively. Microsoft has prepared in advanced for a malformed web page that would attempt to exploit a vulnerability in Notepad. In order to silent such prompts, simply check the box next to "Do not show me the warning for this program again." If you want to turn the prompts back on, make your way to the Internet Options of the browser and reset all settings.