You have to change "Model1" to whatever the actual model name is!

Also, did you array enter the formula?

Array entered** :
** array formulas need to be entered using the key combination of
CTRL,SHIFT,ENTER (not just ENTER)


--
Biff
Microsoft Excel MVP


"Brian" wrote in message
...
igorek, thanks, i would use a pivot table, but i don't know how :(

T. Valko, thank you.
Can i changed that to:

=COUNT(1/FREQUENCY(IF(A2:A7024="Model1",B2:B7024),B2:B7024) )

Which represents the range of the data columns, but it gives me 0?

"Brian" wrote in message
...
Howdy All,

I have a workbook that contains service data for units.

Column A = Model Name (alpha) 87 model names that repeat throughout the
column
Column B = Serial Number (numeric), unique number that repeats throughout
the column
Column C = Service Hours
Column D = Service Req Number

Model Name appears many times in column A
Serial Number appears many times in column b.

I want to determine how many of each Model Number I have with a unique
Serial Number.
But each Model Name and Serial Number can occur many times in their
respective columns if there have been multiple Service Requests.


Thanks,
Brian