I don't have Excel for XP but with older versions of Excel, you will get this problem if your cells are formatted as General.
Highlight the range in question and then right click on the highlighted area. Choose "Format Cells". Select the Numbers tab and choose the "number" category. On the right hand side you should be able to specify how many decimal places you want to see.
Click OK and see if that solves the problem.
Highlight the range in question and then right click on the highlighted area. Choose "Format Cells". Select the Numbers tab and choose the "number" category. On the right hand side you should be able to specify how many decimal places you want to see.
Click OK and see if that solves the problem.
