As a last resort, you can back up a hard-disk drive’s contents on diskettes, a method that is both time-consuming and prone to human error. Also, backing up a full 4-GB hard-disk drive requires approximately 277 diskettes (when using 1.44-MB diskettes),
334diskettes (when using 1.2-MB diskettes), or 139 diskettes (when using 2.88-MB diskettes). Therefore, if it is absolutely necessary to use diskettes as backup devices, any unwanted hard-disk drive files should be deleted before a backup procedure is started.
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Some hard-disk drive failures are recoverable. In these cases you may be able to recover all lost data if the proper utility software is available. Even losses such as acci- dentally deleted files or accidental reformatting of a hard-disk drive can be reversed with these utilities.
If the system is running MS-DOS, many apparent data loss problems are due to cor- ruption or erasure of the hard-disk drive’s master boot record (MBR), MS-DOS boot sector, or file allocation table (FAT); that is, accidental deletion of files or accidental reformatting of the hard-disk drive alters the MS-DOS boot sector, the FAT, and the root directory.
However, such accidents do not actually erase the contents of the hard-disk drive files until new data is written to the sectors containing these files. With software such as the Norton Utilities, Mace Utilities, or PC-Tools Deluxe, the data stored in these areas can often be restored, meaning that you can recover most, if not all, of the data.
Unlike using the format command on a hard-disk drive, using format on a diskette completely erases all the data on the diskette unless you use the diskette format program included in the Mace Utilities.
For a complete description of data recovery procedures and the software needed to perform them, see The Paul Mace Guide to Data Recovery, published by Brady.
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An exhaust fan in the power supply cools the power supply and system by drawing air in through various openings in the system and blowing it out the back. However, the fan also draws dust and other particles into the system, causing contaminant buildup, which results in an increase in the system’s internal temperature and interferes with the operation of various system components.
To avoid these conditions, Dell recommends keeping your work environment clean to reduce the amount of dust and dirt around the system, thereby reducing the amount of contaminants drawn into the system by the power supply fan. In particular, you should keep the exterior of your system and monitor clean, and you should use a commercially available diskette-drive head-cleaning kit to remove contaminants inside your diskette drives.
