Absolute Beginners Guide to A+ Certification. Covers the Hardware and Operating Systems Exam

Win.com in Windows 9x

The Win.com file is responsible for loading the Windows GUI. Normally, Win.com is loaded automatically during the Windows 9x startup process. However, if Windows 9x cannot start correctly, Win.com 's special startup switches can save the day.

The startup switches discussed in the following section can be used in place of making changes to the System.ini file (a specially formatted text file used to adjust how Windows operates). If Windows 9x will start when one or more of these switches is used, add the equivalent statement to the System.ini statement until you solve the underlying problem with your Windows installation or your computer.

To use any of the following startup switches with Windows 9x:

1. Start the computer.

2. Press the Ctrl key (Windows 95) or F8 (Windows 98) after the POST (power-on self-test) has been completed to display the Windows 9x Startup menu.

3. Select the Command Prompt Only startup option (not the Safe Mode command prompt). This option processes the Registry, Config.sys , and Autoexec.bat and boots the system to a command prompt.

4. Enter this command at the prompt and add the desired switches at the end of the command. For example, this command uses four of the possible six switches:

   win/d:fsvx

You can combine the startup switches that can be used with Windows 9x's Win.com . They include

• :F Turns off 32-bit disk access. The equivalent to adding this statement to System.ini is 32BitDiskAccess=FALSE .

• :M Enables Safe Mode. You can also automatically enable this by pressing the F5 key during startup.

• :N Enables Safe Mode with networking. You can also automatically enable this by pressing the F6 key during startup.

• :S Specifies that Windows should not use the ROM address space between F000:0000 and 1MB for a break point. The equivalent to adding this statement to System.ini is SystemROMBreakPoint=FALSE .

• :V Specifies that the ROM routine will handle interrupts from the hard disk controller. The equivalent to adding this statement to System.ini is VirtualHDIRQ=FALSE .

• :X Excludes all the adapter area from the range of memory that Windows scans to find unused space. The equivalent to adding this statement to System.ini is EMMExclude=A000-FFFF .

Use the :M (Safe Mode) and :N (Safe Mode with networking) options if you need CD-ROM support while you're in Safe Mode. Safe Mode doesn't process the Config.sys or Autoexec.bat configuration files, so it doesn't provide CD-ROM support. Add the correct CD-ROM device driver to Config.sys and the matching MSCDEX.EXE command to Autoexec.bat , and boot the computer to the command prompt to load the CD-ROM driver into memory. Then, use the :M or :N switches to start Windows 9x with CD-ROM support.