Let Excel warn me before execute

[time for heroes]

Hello!
Lets say I have a sheet which contains data in columns A-W and from cell 1-3000

I want to create a filter so all duplicates in column A are shown. To do this I:

Mark all data in column A.
Click the 'Conditional Formatting' button
Choose 'Highlight cells rules' and 'Duplicate Values'.

Then I filter on colour and only the duplicates values will be shown.

The problem with this s when I do this on a large set of data excel have problem to do this and just shut down.

Is there any way to let excel warn me that this will take long time to execute before it start the procedure?

Thanks!

[dominicb]

Good afternoon time for heroes

Go to File > Options > Advanced and under Editing Options look for "Alert the user when a potentially time consuming operation occurs".
This gives the option to flag up a message, but you have to set the lower limit. The default (on my machine) is 33,554 cells. You'll need to use trial and error to try and find an acceptable level.

HTH

DominicB

[shg]

If you sort by col A, then you can use a much simpler (faster) CF rule than Format Duplicates