Try this:
Click Start
Click My Computer
Click Tools
Select Folder Options
Click the File Types tab
Scroll down to the file type you want to open with your image editor (BMP, GIF, JPEG, etc....)
Click on it, to highlight it
Click the Change button
Then select your image editor in the list provided
If your editor isn't in the list, click the Browse... button, and navigate to where it's located, and select it
Then put a check in the Always use the selected program to open this kind of file box
Click OK
Click Apply
Click OK
