Excel no longer expects

This is a very stupid thing. Suddenly no longer expects Excel , when you type something .
Probable Cause: The automatic calculation has been turned off .

Remedy:

A) Up Excel 2003
About menu Tools -> Options - > Up tab Calculation - there select Automatic

B) From Excel 2007 Version 1:

Top left clicking on the Excel button in the dialog below right click Excel Options .
Select it, the following dialog formulas left .
Then select Automatic right in workbook calculation.

Version 2:
In the ribbon, select the tab formulas.
Click Turn right calculation options .
Then tick Automatic.

Possible causes:

1. accidentally changed itself
2. Irdenein Dödel has disconnected them about these macros and forget to turn
3. Other ...