The A+ Exams Guide: (Exam 220-301), (Exam 220-302) (TestTakers Guides)

Several DOS command prompt utilities can be very useful to a computer technician for memory configuration and hard drive or floppy disk preparation. A few of the more useful DOS utilities are described next, with an emphasis on how some of them are used through the GUIs of newer operating systems.

FDISK and FORMAT

The two DOS command line utilities FDISK and FORMAT were described in detail in Chapter 7. It is important to remember that FDISK is a disk-partitioning utility used to separate one physical hard drive into 24 logical partitions for more efficient use of storage. FDISK also makes it possible for you to install multiple operating systems on one physical drive.

Before you run FDISK, consider which operating system or systems you are going to install and how much space you need to allocate for each partition. Keep in mind that different BIOS settings can affect the size of the partitions you can create, and that various file systems require different cluster sizes.

DOS uses a FAT16 partition table. The maximum size of a FAT16 partition is 2.1GB. Windows 95 B/C and Windows 98 use a FAT32 partition table that allows for a single partition to reach 2TB (terabytes) in size.

Following are some important notes about FDISK.

• You can use the FDISK command FDISK/MBR from a DOS prompt to construct a new Master Boot Record (MBR) if yours has become corrupt or infected by a virus.

• You can partition a disk in Windows 2000 using disk management (this is discussed in Chapter 13).

• FDISK is accessible from a bootable floppy disk, which can be useful for troubleshooting undetected hard drive issues. For example, suppose you have a desktop or laptop system that does not detect a hard drive when booted. You can boot to a bootable floppy disk and run the FDISK utility on the undetected hard drive to see if the drive is configured properly.

The FORMAT utility is used to prepare a hard disk or floppy for a file system. Remember, FORMAT.COM creates the FAT (File Allocation Table) and the root directory on a hard disk or floppy disk.

The syntax for formatting a floppy disk from a DOS or Windows command prompt is as follows.

C:\FORMAT A: /S

The /S option copies the three system files necessary to make the disk bootable.

To format a floppy disk in Windows 9.x or Windows 2000, simply insert a blank floppy disk into your 3.5-inch floppy drive, navigate to Windows Explorer, and right-click the 31/2 Floppy (A:) icon (drive A:). Next, left-click Format. The Format A: window appears. Click Start to begin the formatting process.

SYS

As mentioned above, SYS is really a DOS command. It is used to copy the three main DOS system files (IO.SYS, COMMAND.COM, and MSDOS.SYS) to a disk. The proper syntax for using the SYS command is C:\SYS A:. The message “System transferred” appears after the command has been entered.

This is an easy way to transfer the system files to a disk without going through the whole format routine. If you are missing the important system files on your hard drive, you can also use the SYS command to SYS C: from a floppy.

CHKDSK and ScanDisk

CHKDSK is an old DOS utility that was used to search out bad clusters and lost allocation units on a hard drive. It was common to implement the CHKDSK /F command to attempt to repair bad clusters. The CHKDSK utility has been for the most part replaced by the ScanDisk utility. ScanDisk is a Microsoft disk analysis and repair utility that is used to recover and repair lost or bad clusters on a disk. Windows 9.x and Windows Me utilize a GUI version of ScanDisk that can be accessed and run by selecting Start > Programs > Accessories > System Tools > ScanDisk. You can use the GUI version of ScanDisk to scan your floppy or hard disk. You will have the option of running a standard scan, which checks files and folders for errors, or a thorough scan, which also scans the disk surface for errors. For best results, make sure that you select the thorough option and place a check mark in the “Automatically Fix Errors” box before you start the scan.

To check a disk for errors in Windows NT, Windows 2000, and Windows XP, open My Computer and right-click on the drive you wish to check. Select Properties > Tools, and under Error-checking, select Check Now...; a Check Disk message box will open, and you will have the options to “Automatically fix file system errors” and “Scan for and attempt recovery of bad sectors.” You should then select both options and click Start. If you are checking your system drive, you will receive a message stating that the disk check could not performed because the check utility needs exclusive access to the drive. In the same message box, you are asked if you would like to schedule the check on the next restart of your computer. If you select “Yes” the check utility will run the next time your computer is restarted.

Defrag

Defrag is a DOS and Windows utility that improves system performance by placing files that are fragmented into a contiguous order on a hard or floppy disk. In the Windows world, the program is actually called Disk Defragmenter. This tool can be run from Windows 9.x/Me/2000 or Windows XP by selecting Start > Programs > Accessories > System Tools > Disk Defragmenter. Alternately, you can open My Computer, right-click the C: drive, left-click Properties, select Tools, and select Defragment now. Windows NT does not come with a built-in defrag utility.

Keep in mind that there are usually at least three ways to accomplish the same task in a typical Windows GUI. You must practice these concepts and explore others if you want to become a well-rounded technician. See if you can find a third way to use the defragmenter utility in Windows 9.x. Here is a hint: Start > Run >...

SMARTDRV.EXE

SMARTDRV.EXE and SMARTDRV.SYS make up a 16-bit disk caching utility that is used to improve the access speed to data stored on a hard drive in a DOS or Windows 3.x environment. The SMARTDRV line is only used in the AUTOEXEC.BAT file. Windows 9.x uses a 32-bit program known as VCACHE in place of SMARTDRV. VCACHE can automatically adjust the hard drive’s cache size based on the needs of the operating system and programs.

MSD.EXE

MSD.EXE is a DOS-based utility that is executed at the command prompt. It is used to view information on the system configuration, including devices, memory, video display, mouse, disks, ports, and TSR programs. In the old DOS days, MSD was a very useful program that provided vital information for troubleshooting. Although MSD.EXE is included on the Windows 9.x installation CD-ROM, most people prefer to use the Device Manager in Windows 9.x for troubleshooting purposes.

POWER.EXE

POWER.EXE is an optional program that is loaded in CONFIG.SYS. If your computer supports Advanced Power Management (APM), the POWER.EXE driver can be loaded to reduce the amount of power a system uses when it is idle.

The syntax for loading the POWER.EXE device driver in the CONFIG.SYS file is as follows:

DEVICE=[drive:] [path] POWER.EXE

POWER.EXE has proven to be a very useful tool for conserving battery life in laptop computers.

LABEL.EXE

The LABEL.EXE utility is used to create, change, or remove the name of a disk. The LABEL command can be used in DOS, Windows 9.x/Me/NT/2000 or Windows XP to create a volume name of up to 11 characters, including spaces. Use the following syntax to label a floppy disk:

C:\LABEL A: [Enter a label name up to 11 characters in DOS.]

DEBUG.EXE

DEBUG.EXE is simply a DOS program that is used to debug or test programs. Changes made to programs using DEBUG.EXE cannot be undone; therefore, only advanced users should use it.