How to shade every other row in Excel 2007 or Excel 2010

To use the Conditional Formatting option to shade rows in a worksheet, follow these steps:

1. Open the worksheet.
2. Select the cell range that you want to shade, or press Ctrl+A to select the whole worksheet.
3. Click the Home tab.
4. In the Styles group, click Conditional Formatting, and then click Manage Rules.
5. Click New rule.
6. Click Use a formula to determine which cells to format.
7. In the Format values where this formula is true box, type =MOD(ROW(),2)=1, and then click Format.
8. On the Fill tab, click the color that you want to use to shade every other row, and then click OK.
9. Click OK to close the New Formatting Rule dialog box.
10. Click Apply, and then click OK to close the Conditional Formatting Rules Manager dialog box.

To use the Format as Table option to shade rows in a worksheet, follow these steps:

1. Open the worksheet.
2. Select the cell range that you want to shade, or press Ctrl+A to select the whole worksheet.
3. Click the Home tab.
4. In the Styles group, click Format as Table, and then click the style of formatting that you want.
5. In the Format as Table dialog box, click OK.

http://support.microsoft.com/kb/919194