I have a macro that copies data from one cell to another and uses a VLOOKUP formula, among other things. My spreadsheet contains nearly 2000 rows. When I run it in Excel 2003, Excel starts to slow down as the macro processes rows 500 and above. It gets even worse when it reaches the 1000th row. It takes more than 5 hours to complete. In Excel 2007, however, the macro runs for only half an hour. Can anyone help me find a good solution?