OK I have Windows ME and the JPG icon is the same as "WordPad" icon and sometimes all my icons on my desktop and in certain folders change to the same icon but as far as the image icons go you do the following.......
1. right click on a picture or image that you know is a "Bmp" file
and a drop down menu will appear
2. point to and click on "Open With"
3. choose "Paint"
4. It should ask if you want all to open with this program you click yes
then apply then OK now you will see the real .Bmp icons
This probably doesn't help you much but I am trying anyway
Right click the icon whether it be a .txt icon or not, go to Properties and you'll see "Program Name.txt" in the General Tab, just change the ".txt" to ".exe" and that should be it. A Dialogue will pop up saying "If you change the file extension, the file may become unusable. Are you sure you want to change it?" Just click Yes.