IFERROR was introduced in Excel 2007... it is not available in Excel 2003.

You need to use ISERROR with IF to get similar functionality
Instead of
IFERROR( Your formula, value if error )
use
IF( ISERROR(Your formula), value if error, Your formula)

"Mike" wrote:

I am using excell 2007 & this formula works
{=IFERROR(AVERAGE(IF(MOD(COLUMN(G5:HC5)-COLUMN(G5),4)=0,IF(G5:HC50,G5:HC5))),0)}
When i upload this workbook to a 2003 version this formula does not work I get
{=_xinfl.IFERROR(AVERAGE(IF(MOD(COLUMN(G5:HC5)-COLUMN(G5),4)=0,IF(G5:HC50,G5:HC5))),0)} or somthing close to this
Then in the cell with this formula has a NAME error WHY & HOW could i fix