You know when you install a new program (lets say photoshop example) and they have their own format (in this example PSD). If you have a psd file and you open it a pop up will prompt you giving you two OPTIONS. 1: Use the internet to look for a suitable program to RUN this file. 2: Pick a program from the computer to run this file. You know when you pick option 2 there is a box saying "Always use this program to run this type of file" if I tick tick that and pick photoshop later on how can I change that psd file in to type of file (unknown format type), Hope you understand =\Use "Open With..." and select browse.

Oh no I know that. I mean after I do that with "Always use the selected program to open this kind of file" how WOULD I change it back to kind of icon?
That's the only way I know.
Change to another program, always use it, reboot your computer, the icon will change.Are you asking how to make Windows forget which program to use or do you just want to change the icon?

To make Windows forget...
1) Go to "Control Panel" and then "Folder Options".
2) Go to the "File Types" tab.
3) Select the extension you want to change and click "Delete".
4) Click "OK".
Now, Windows will not know which program to use to open the file.

To change the icon...
1) Go to "Control Panel" and then "Folder Options".
2) Go to the "File Types" tab.
3) Select the extension you want to change and click "Advanced".
4) Click "Cange Icon..." and browse to the icon you want. (To use the "unknown file type" icon, type "C:\WINDOWS\system32\shell32.dll" in the "Look for icons in this file" FIELD.)
5) When you have the icon you want, click "OK" in the three windows.
Now, Windows will know which program to use to open the file but it will show the "unknown file type" icon.Quote from: Kip on September 27, 2009, 11:37:40 AM

Are you asking how to make Windows forget which program to use or do you just want to change the icon?

To make Windows forget...
1) Go to "Control Panel" and then "Folder Options".
2) Go to the "File Types" tab.
3) Select the extension you want to change and click "Delete".
4) Click "OK".
Now, Windows will not know which program to use to open the file.

To change the icon...
1) Go to "Control Panel" and then "Folder Options".
2) Go to the "File Types" tab.
3) Select the extension you want to change and click "Advanced".
4) Click "Cange Icon..." and browse to the icon you want. (To use the "unknown file type" icon, type "C:\WINDOWS\system32\shell32.dll" in the "Look for icons in this file" field.)
5) When you have the icon you want, click "OK" in the three windows.
Now, Windows will know which program to use to open the file but it will show the "unknown file type" icon.