How to help prevent file corruption in Excel

This article discusses features that are available in Microsoft Excel that are designed to help prevent data loss. This article also discusses general things that you can do to help prevent file corruption.

AutoSave

Microsoft Excel 97 and Microsoft Excel 2000 include an AutoSave feature. You can customize this feature to automatically save your file at set intervals of time. The AutoSave feature does not make a backup copy of your file. Therefore, it does not help protect against file corruption. Instead, it helps protect your data if Microsoft Excel unexpectedly quits. For example, it helps protect your data if your computer unexpectedly loses power.

For additional information about how to use AutoSave in Excel, click the following article number to view the article in the Microsoft Knowledge Base:

AutoRecover

In Microsoft Excel 2002 and in Microsoft Office Excel 2003, the AutoSave feature has been replaced with the AutoRecover feature. The AutoRecover feature is similar to the AutoSave feature because it saves the file at set time intervals. However, it is different from the AutoSave feature in that instead of saving the file itself, the AutoRecover feature saves a copy of the file to a specified location.
For additional information about how to use the AutoRecover feature in Excel 2002 and in Excel 2003, click the following article number to view the article in the Microsoft Knowledge Base:

Automatic backup

Microsoft Excel includes an Always Create Backup option. This feature always saves the previous version of your Excel workbook when you save changes to your current Excel workbook. This helps protect against file corruption. However, the information in the backup file will be one save out of date. That is, the backup file will not include your most recent set of saved changes.

This option can be accessed from the Save As dialog box by clicking General Options on the Tools menu. By default, this option is not selected. When you select this option in a file, it is set for that file only. To change this option for all new documents, modify the template for the default startup worksheet or workbook.

Hard disk maintenance

Your computer's hard disk is a mechanical device with moving parts. Like all mechanical devices, it will eventually wear out and fail. Hard disk manufacturers frequently measure the reliability of their drives as the average number of hours before failure or "mean time between failure" (MTBF).

As a hard disk wears out, sections of it become unreadable and are frequently referred to as bad sectors. One side effect of this is file corruption. If a file is stored on a section of the hard disk that becomes unreadable, the file can no longer be retrieved.

One method for combating file corruption is to perform maintenance on your hard disk regularly. One recommended schedule involves running ScanDisk or a third-party hard disk utility to examine the file structure of the hard disk one time per week. Then, run the utility one time per month to perform a surface scan of the hard disk media. For more information, see the manual for the maintenance utility program. Note that if you have Microsoft Plus! for Windows 95, you can use the System Agent to schedule ScanDisk to automatically run.

Other troubleshooting steps that you can take to help prevent file corruption include the following:

• Exit Windows before you restart or shut down the computer.
• Move sources of electromagnetic radiation, such as radios, fax machines, televisions, stereos, speakers, and so on, away from your computer.
• Do not put floppy disks on top of a computer monitor. A computer monitor is a source of electromagnetic radiation.
• Regularly scan your computer for viruses.
• Store floppy disks in a disk storage container, such as the box the disks came in, to prevent dust from building up on the disks.
• Prevent dust from building up around your computer.

Backing up data

One of the best ways to prevent data loss is to back up data regularly. The more important your data is, the more frequently you should back it up.

If you consider your information to be critical, we recommend that you save your files to at least two different locations. At least one of these should be a removable media, such as a floppy disk or a computer tape. The removable media should then be stored in a fireproof safe. Note that there are different grades of fireproof safes. For removable media to survive a fire, the interior temperature of the safe must not exceed 110 degrees Fahrenheit during the fire. Contact the manufacturer of your safe for more information.