Open .ico with Photoshop

windows-vista-icon 

  1. download from this site,
  2. open the zip file,
  3. find the folder (File Formats) in your computer, in Windows: C:\Programs\Adobe\Adobe Photoshop CS3\Plug-Ins\File Formats,
  4. copy the file ICOFormat.8bi from zip inside this folder 
  5. open Photoshop
  6. now, when you want to save a .ico file in the list save as… is also the ext .ico.