Bootable Rescue Disk, Diagnostic Cards And Diagnostic Software

Bootable Rescue Disk

An essential tool for PC troubleshooting is a bootable rescue disk. In fact, a good PC technician will have as part of his or her toolkit a bootable rescue disk for every operating system version. Not only can it boot the PC even when the hard drive fails, but you are assured the cleanest boot possible.

A “clean boot,” is one that does not load any extraneous software, drivers, or other memory-resident programs (TSRs), which might be loaded from startup routines on the hard drive.

To make a DOS bootable disk using the same version of DOS that’s on a computer’s hard drive, use this command:

C:\> FORMAT A:/S

The /S option tells DOS to copy to the disk the files needed to load DOS from it. The /S command also puts the two DOS hidden files (IO.SYS and MSDOS.SYS for Microsoft DOS; IBMBIO.COM and IBMDOS.COM for IBM DOS) and COMMAND.COM on the disk. The disk will include a small boot record that identifies the disk layout and the names of the two hidden files. It’s important that the boot disk have the same version of DOS that is on the hard drive. If you’re consistent with versions, then once you’ve booted you can use some of the DOS loaded from the disk and some DOS program files on the hard drive, without DOS displaying error messages about using different versions. Use the VER command at the DOS prompt to display the current version of DOS. You can also add some DOS utility commands to the disk so it can serve as a rescue disk if needed. In addition to the boot files, copy these files to the disk:

ATTRIB.EXE

CHKDSK.EXE

EDIT.COM (which may also require QBASIC.EXE if you are using an older version of DOS)

EMM386.EXE

FDISK.EXE

FORMAT.COM

MSCDEX.EXE

SCANDISK.EXE

SYS.COM

DEFRAG.EXE

HIMEM.SYS

UNDELETE.EXE

For Windows 9x, make a rescue disk. To make a rescue disk for Windows 95, also include the files needed to access the CD-ROM drive without depending on the hard drive. Windows 98 places these real- mode driver files on the disk automatically.

Diagnostic Cards And Diagnostic Software

Although they’re not essential, many hardware and software tools can help you diagnose a PC problem. Before purchasing these tools, read the documentation about what they can and cannot do, and, if possible, read reviews about the product. The Internet is a good source of information.

Diagnostic cards are designed to discover and report computer errors and conflicts at POST. If you have a problem that prevents the PC from booting, you can install the diagnostic card in an expansion slot on the systemboard and then attempt to boot. The card monitors the boot process and reports errors, usually as coded numbers on a small LED panel on the card. You then look up the number in the documentation that accompanies the card to get more information about the error and its source.

Examples of these cards are:

POSTcard V3 by Unicore Software, Inc. (www.unicore.com)

Post Code Master by MSD, Inc. (www.msd.com)

POSTmortem Diagnostics Card by System Optimization, Inc. (www.sysopt.com)

Diagnostic software is generally used to identify hardware problems. If the software rates itself as being at the professional level, it generally assumes greater technical expertise and also provides more features than end-user or novice- level software. The most effective diagnostic software does not run from the operating system because the operating system can sometimes mask a hardware problem. Here are a few examples of diagnostic software:

PC-Technician, by Windsor Technologies, Inc., is a professional- level PC diagnostic software that loads and operates without using the PC’s installed operating system because it has its own proprietary operating system built in. Results are thus unaltered by any errors in the PC’s operating system.

PC-Diagnosis, also by Windsor Technologies, Inc., is a software program designed for less experienced PC technicians and end users. It contains a small subset of the features of PC-Technician, thus reducing the cost of the product. It’s easy to use and includes its own proprietary operating system so that the PC’s operating system will not mask results of the diagnostic tests.