Apple PowerBook (2400c) - Manual (Page 89)

When I try to open a document, a message says the program can’t be found.
m The document may have been created with a program that is not on your
hard disk, or with a different version of the program.
m You can also open a document from within a program by using the Open
command in the File menu. For more information, see the documentation
that came with your programs.
m If you know the correct program is on your hard disk, there may be a
problem with the information that the computer uses to keep track of files.
Restart the computer and hold down the Command (x) and Option keys
until you see a message asking if you want to rebuild the desktop. Release
the keys and click OK.
Note: If you have Mac OS Easy Open installed, you must use the
Extensions Manager control panel to turn off all extensions except the Mac
OS Easy Open control panel, and then follow the steps given above to
rebuild your desktop.
A window has disappeared.
m Another open window may be covering the one you’re looking for. Move,
resize, close, or hide windows until you see the one you want.
m The program the window is associated with may be hidden. Choose Show
All from the Application menu, then click the window you want, or choose
the program from the Application menu.
89 Tips and Troubleshooting