Most of the time when you're sorting in Excel, you sort based on the values in one or more columns. If your workbooks are like mine, it's rare that you sort horizontally, based on the values in a row.
It is possible though, and you can sort in ascending, descending, or custom sort order.
Change the Sort Options
To sort by row, click the Options button in the Sort dialog box. Then, in the Sort Options, select Sort Left to Right.
In the screen shot below, the total row has been sorted, so the month with the highest total is at the left.
Excel 2010 Sorting
So much has changed in Excel 2010 and Excel 2007 sorting, that I've finally updated the sorting in Excel page on the Contextures website. You can find the detailed instructions for sorting by row, and other sorting tips.
There is also an Excel sorting sample workbook that you can download, at the bottom of the sorting page.
Watch the Excel 2010 Sorting Video
To see the steps for sorting a row in Excel 2010, you can watch this short Excel video tutorial.
Or watch the video on YouTube: Sort Data in Excel Rows