Change File Extension Name

A filename extension is a suffix to the filename applied to indicate the file format of its contents. In Windows, usually, the file extension contains 3 letters (e.g. AVI, JPG, DOC, XML, PDF) or 4 letters (e.g. DOCX, XLSX).

By default, Windows hides file name extensions to make file names easier to read, but you can choose to make extensions visible. If you need change a file extension name in Windows, you need to first make the extension names visible:

Please open Windows Explorer, go to menu Tools, Folder Options.

Click on the View tab and if the option "Hide Extensions for Known File Types" is active, de-select it.

Then the extension name of the files will be shown in Windows Explorer and you may proceed to rename the file as you need. Right click on the filename you need to rename, then choose "Rename". Press "End" button to move to the end of the filename and change the extension name, and Press "Enter" to complete the extension name change. Windows will prompt you that changing the file name extension might cause the file to stop working properly. If you are certain that the extension you typed is one that the program you are using will understand, click Yes to confirm the change.

The following characters cannot be used in a file name (including extension name):

You cannot use any of the following characters in a file name: \ / ? : * " > < |

Repair Corrupted Excel File

For the corrupted Excel file (.xls, or .xlsx), Excel 2003 or 2007 has built-in repair feature, and it can recover some corrupted or damaged Excel files. For the files cannot be repaired and open Excel, you may use some third-party tools to recover them:

ExcelRecovery from Recoveronix Ltd. (www.officerecovery.com)

• Supports all modern file versions, including Excel XP, Excel 2000, Excel 97, Excel 95 and Excel 5.0.
• Recovers cell data: text and numbers as well as formulas.
• Restores formatting.
• Restores structure of multi-sheet files.
• State of the art recovery engine, designed to fix worst injuries.
• Easy to use. No special user skills required.
• Available for all modern platforms: Windows 95/98/NT/2000/ME.

Usage:

Using ExcelRecovery As A Standalone Application

1. Start ExcelRecovery.

2. Select the Recover... item in the File menu. A file selection dialog will open.

3. Select the file corrupted to recover.

4. Press the "Recover" button to start processing the file.

5. Wait until the file processing is completed.

6. When prompted, save the recovered file, assigning it a new name.

Disclaimer:

Actual results of recovery depend on how damaged a particular document is.

Other Excel File Repair or Recovery software:

Advanced Excel Repair (from DataNumen)

Advanced Excel Repair is a powerful tool to recover corrupted Excel XLS and XLW files. It uses advanced technologies to scan the corrupted Excel files and recover your data in them as much as possible, so to minimize the loss in file corruption. Main features include: recovers cell data including texts, numbers, and formulas; restores structure of multi-sheet files; restores worksheet names; recovers Excel files on corrupted medias, such as floppy disks, Zip disks, CD-ROMs; repairs a batch of Excel spreadsheet files; supports integration with Windows Explorer, so you can fix a XLS file with the context menu of Windows Explorer easily; supports drag & drop operation; supports command line parameters.

Excel Workbook Rebuilder (from vbusers.com)

The Workbook Rebuilder has been highly recommended on several Microsoft newsgroups. The rebuilder fixes corrupt workbooks and overcomes many problems including unexplained errors and Excel locking up while saving and opening workbooks.