Tools | Options | [Calculations] tab. Set it to Manual calculate. The file
opening and operating should be faster, however, you will have to press [F9]
(and be prepared for a wait) when you want to update the values based on any
changes you've made.

Other thing to watch out for - when you open a workbook that has calculate
set to manual and don't close Excel, the next workbook(s) you open will also
get their calculate operation set to Manual.

"Irfan" wrote:

I have a file containing array formulas for sum if. Whenever I update the
cell it take too long to calculate in Excel 2002. or if i try to open it in
Excel 2003 it took around 5-10 minutes to open the same file.