Apple PowerBook (Duo, 2300 Series) - Manual (Page 97)

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 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 Macintosh Easy Open is on, you must turn off all extensions
except the Macintosh Easy Open control panel before rebuilding your
desktop. (Macintosh Easy Open is turned on at the factory.)
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.
Other problems while working
The screen went blank.
m Screen dimming may be on. Move the pointer to restore the screen’s
brightness. You can adjust the interval before screen dimming takes effect,
or you can turn screen dimming off, using the PowerBook control panel.
m The computer may have gone to sleep. Press any key on the keyboard
(except Caps Lock) to wake it.
m The battery may be drained. Install a charged battery, or plug in the power
adapter and let the battery charge for a few minutes. Then try to wake or
start up the computer. (You can also use the optional recharger.)
89 Tips and Troubleshooting