An icon is blinking in the menu bar.
mA program needs attention. Open the menu and choose the program whose icon is blinking (it may have a diamond by its name). Respond to any messages on the screen. If it’s not clear what you should do, consult the documentation that came with the program.
A file can’t be thrown away.
mThe file may be locked. Select the file’s icon, then choose Get Info from the File menu and click the Locked checkbox to remove the X. You can delete locked files that are in the Trash by holding down the Option key while you choose Empty Trash from the Special menu.
mAn application program may be using the file. Close the file or quit the program.
mIf the file is on a floppy disk, the disk may be locked. Unlock the disk by sliding the tab so that it covers the hole at the corner of the disk.
mThe file may be in a shared folder that can’t be changed. You can throw away the file by turning off file sharing temporarily (click Stop in the Sharing Setup control panel). Or you can select the shared folder, choose Sharing from the File menu, and uncheck the box labeled either “Can’t be moved, renamed, or deleted” or “Same as enclosing folder.”