The Power |
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by Robert J. Beasley |
If you are running DOS 6.x or Windows 95, the F8 function key can be an extremely powerful tool to be used for diagnosing problems you might be having. In DOS 6.x by pressing F8 during the boot process prior to loading the CONFIG.SYS and AUTOEXEC.BAT files, you can step through each of these files one line at a time and you are given the option of either loading the line or skipping it.
By stepping through the files one line at a time, you will be able to see any error message which might appear as the line is executed. By doing this you can isolate any load problem you might be having. If you don't receive an error message, you can use the same procedure to choose not to load selected drivers or programs, thereby booting your system with a different configuration. You might even try it sometime even if you aren't having a problem just to see what you are loading into your system when you are booting your machine. It lets you see all of those changes that the programs you have loaded into your system have done for (to) you.
I have been talking about DOS 6.x to this point. Windows 95's F8 is different in that it gives you more options. When you press F8 during Windows 95 load you are presented with six options:
1. Normal
2. Logged (\bootlog.txt)
3. Safe Mode
4. Step-by-step configuration
5. Command Prompt Only
6. Safe Mode Command Prompt Only
Normal allows you to load your system with your normal configuration. This can be used if for some reason your last boot was abnormally interrupted and you would like to continue the boot with your "normal" configuration. The second option, Logged (\bootlog.txt) uses a file created during your boot process. It is a text file called "bootlog.txt" which can be found and viewed as a text file in your root directory C:\.
The third option and the one that 1 have found useful for trouble shooting is Safe Mode. Safe Mode will boot your system with a minimal configuration. You will come up in 16 colors with only your necessary drivers loaded: i.e., drivespc.drv, if you compressed your drive. None of the programs in your start-up directory will be started.
I recently purchased and installed a new program. Whenever I tried to access files using the scroll bar in the files menu, the application would terminate. It was consistent and crashed each time I tried using the scroll bar. After talking to tech support and getting no help from them (what a surprise!!), I decided to see if to see if I could figure out what was happening.
I rebooted my system in Safe Mode, started the application, and it worked normally. I therefore figured that something I had running in Windows 95 must be conflicting with the application. I next rebooted my system in Normal Mode. I then used Ctl-Alt-Del (This does not reboot your system in Windows 95; it brings up a list of applications which are running and you can select individual applications and terminate only that application).
I next stopped applications one at a time and would restart the application with which I was having problems and would check for the error I was encountering.
When I stopped an application and my failing program worked correctly, I knew I had found the application with which it was conflicting. I restarted my program a third time, stopped only the application which I had discovered in the above procedure, and all worked as advertised.
By using the Safe Mode I had determined there was a conflict and was able to isolate the conflicting program. I can now stop the conflicting module whenever I am running the new program and restart the conflicting module after finishing with my new program.
The fourth option is a "step-by-step" option which operates just as the DOS 6.x F8 operates and allows you to step through your start-up files line by line. The fifth option allows you to start up in Command Prompt Only mode. You come up in DOS mode without loading the Windows 95 desktop. Finally, the sixth option is Safe mode Command Prompt Only. This allows you to get into the "DOS prompt" mode with minimal configuration of drivers.
As the title of my articles says, F8 is an extremely powerful tool which comes with your operating system but is "little noted nor long remembered." It is better documented in Windows 95 than in DOS 6.x. Having found out about F8, I often wonder how I have lived without it in the past. I know what I had to do in the past to remark out lines in my start-up files to isolate problems, but with F8 things became much simpler.
Reprint from User Friendly, the Journal of the Los Angeles Computer Society.
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