By default, the Excel workbook will be saved in the format of .xlsx. If you need to export the data of active worksheet to a CSV file, you can use the Save As command with the following steps:
Step 1: Activate the worksheet you want to export or save as a CSV file, and click the Save as button under the File tabin Excel 2010, it shows the Save as dialog box. In Excel 2007, click Office Button and Save As button to open it.
Step 2: Type the Name for the CSV file, and select the folder where it will be saved in.
Step 3: Then in the Save as type area, select CSV (Comma Delimited) from the drop down list. See screenshot:
Step 4: Click the Save button in the Save As dialog box.
Step 5: It shows a warning dialog box asking you to save only the active sheet as a CSV file, click OK. See screenshot:
Step 6: Another warning dialog box comes out asking you to leave out any incompatible features with a CSV file, clickYes. See screenshot:
Note: the Save as command only exports the data of active worksheet as a CSV file The CSV file formats that you should choose to export data in Excel 2007/2010 is:
CSV (comma delimited) format: Saves a workbook as a comma-delimited text file for use on another Windows operating system, and ensures that tab characters, line breaks, and other characters are interpreted correctly. Saves only the active sheet.