On some workstations the signatures and ad banners may appear incorrectly, as in the picture below. The following article describes how to correct this problem.
Step 1: Open the Registry Editor. You can do this by choosing Start / Run and typing regedit then click OK.
Step 2: Locate the class handler for *.bmp. You can find this in the left pane of the Registry Editor under HKEY_CLASSES_ROOT. It will be a folder called .bmp.
Step 3: With the .bmp folder highlighted, the right pane should appear as in the picture above. Double click the (Default) item. The value data should read Paint.Picture. Click OK to close the Edit String dialog box.
Step 4: If you have inserted a signature into a letter, or an image into the ad banner, you must now go and remove it and add it back. Your image should now appear normally as in the picture below.