Here is how to use Watch Window in Excel.
Adding a Watch Window
Select the cells you want to watch. On the Formula tab, in the Formula Auditing group, click on Watch Window.
Click Add Watch.
Note: You can move the Watch Window toolbar to the top, bottom, right or left side.
To display the cell that an entry in Watch Window toolbar refer to, double click the entry.
Removing cells from the Watch Window
Select cell that you like to remove. To select multiple cell, press CTRL and then click the cells.
Click Delete Watch.