Originally posted on 07/05/2012:

Open your worksheet.

Press CTRL END.

If you end up at the bottom of the whole sheet, and especially if this is the case on numerous sheets, that's the problem. I've faced it before a few times, I think generally from Copying and Pasting entire columns. When the entire gazillion available cells in a sheet have to be checked every time you do anything, the system bogs down.

Copy the cells you actually need to work into a clean sheet, delete the old sheet, and you should be fine. For example, if the cells you're actively using are, say, ending at JY106, but CTRL END brings you to whatever, row 100,000+, etc, then just completely copy from A1 to JY106 into a new sheet, then delete the old sheet.

If your data is filling up entire sheets, then yes, you have to change to something other than Excel.