On windows 7 instead of opening GIF on IE8 (The default) I set it to FF. When viewing the image on 'details' setting GIF images has a firefox logo instead of what they had before. How do i set it back? or select an ico (such as the one on XP).
The icon depends on which application you have set to be the default for that file type. Because you've set it to be Firefox, Windows is using the FireFox icon.
I've found this page which describes the process for Vista and Windows 7. You have to edit the registry. There are third party tools you can use:
The following is from a Windows XP machine, but I thought the process was basically the same. However, there's no File Types tab in Windows 7, so this approach won't work.
Select Tools > Folder Options... then the File Types tab.
Select "GIF" from the list of files and then Advanced.
Next to the current icon and description there's a button labelled Change Icon. You can either select the image from the current dll it uses or change the icon file it uses via the Browse button.
Right-click, select Open With and Choose Default Program. Make sure the "Always use the selected program..." check box is checked.
Edit: In hindsight I'm guessing you want to keep Firefox as the associated program, but change the icon, is that right? Your question isn't 100% clear.
Maybe this is what you need? change icon in Windows 7 & Vista