See
http://support.microsoft.com/?kbid=211922
on this.

HTH. best wishes Harald

"Sajid Siddique" skrev i melding
...
Dear Sir/Madam,

By default there are only sixteen undo level in Microsoft
Excel.But
i want to increas undo level more than sixteen. Please guide me how can i
solve this problem? I will be very graetful to you. Thank you.