When I enter a formula, I get a #NAME? error. What does it mean?
The most likely cause for this error is that you're entering the range name incorrectly. Try using the Insert, Name, Paste command to ensure the range name in your formula is correct.
I created a formula that referenced a workbook file that was created by one of my co-workers. Today Excel says it can't find the file my colleague created. What do I do?
Check to see whether your co-worker deleted, moved, or renamed the file. The formula won't work if the file is gone or moved. If the file has a new name or a new location, update your formula accordingly.
I work on a laptop connected to a network that I take home at night. Why do formulas that work in the office produce errors at home?
If your formulas reference files on the network, Excel won't be able to see them if you're not connected.
How do I know whether Excel is computing my formulas correctly?
Excel doesn't make mathematical errors, so you don't need to worry about calculation mistakes. However, you still need to make sure your worksheet has been set up correctly. If your worksheet contains incorrect numbers or percentages, the calculations based on them will be wrong as well.
Why does my worksheet display the word Circular with a cell address beneath the sheet tabs on the status bar?
A circular reference means that a formula you entered into a cell references itself. Excel displays the word Circular with the cell address that contains the incorrect formula. For example, if the formula in cell G31 reads =SUM(G15:G31), the formula contains a circular reference. The word Circular and cell G31 appear beneath the sheet tabs on the status bar. Formulas should never reference the cell in which they're located.