Bitmap Fills that are incorporated in either a drawing or symbol file are "referenced". If you simply copy the drawing or symbol over, and not the actual bitmap it will not show and you will get the image map "Image not Found" where the actual bitmap fill should appear. The other possibility is that you did copy over the bitmaps as well as the drawing or symbol, but the path structure is not correct, so the bitmap is not found. To resolve the problem do as follows:

1. Copy the bitmaps on to your home computer into a folder of your choosing or into the same folder as the drawing or symbol file
2. Open the drawing or symbol file. If the bitmaps were copied to the same folder as the drawing or symbol they may already be resolved. If not continue with 3 below
3. Open the Directory dialog (Ctrl + Right mouse click on the empty drawing screen and select Directory...)
4. Open the Images tab
5. The missing images will be listed in the dialog with an X next to each one that has either a missing image file or incorrect path. To the right of the image name click the ... button
6. Browse to the folder where the images were copied and select the corresponding image. A tick mark will now appear once the unresolved issue has been corrected.