Where does IE9 look for the large favicons?

Question

IE9 has the concept of pinning a particular website to the Windows7 task bar. For certain sites (such as Facebook), it will then display an extra large favicon in the task bar,

Answer 1

Please read the following article
How to enable IE9 pinning and Jumplists

Create a High Definition Favicon

Standard favicon files are usually 32x32 or 16x16 pixels in size. These look great in the browser but when you pin it to the taskbar it can be a little small and pixilated.

To give the best pinning experience you should use a 64x64 favicon. I used http://www.favicon.co.uk/ to create a 64 x 64 icon file and then uploaded it to my site.

You then need to make sure you are using the new favicon by checking the tag is pointing at the new 64x64 fav.ico file.

Basically you now can create a larger favicon file, and IE9 will use it in the task bar. However, if you have a standard size favicon, IE9 will still use it.

An added benefit is that you can implement an awesome JumpList to enhance the visitors browsing experience.

Further reading: http://www.hanselman.com/blog/IE9SiteSpecificBrowsersAndAddingYourOwnJumpListItemsToPinnedTabs.aspx