Tricks of the Trade: Editing and Managing System Startup Files

Most longtime Windows systems administrators (i.e., those who've been around since the Windows 9x days) have probably used the old System Configuration Editor. This tool, which you launch by typing "sysedit" (don't type the quotation marks) at the Run command prompt, has been around since the early versions of Win9x and brings up a text editor similar to Notepad with the win.ini, system.ini, autoexec.bat, and config.sys files already open. The config.sys and autoexec.bat files for users of Windows XP, Windows 2000, and Windows NT 4.0 don't have any content because Microsoft provides these files only for Win9x compatibility. However, many systems administrators still use System Configuration Editor to take a quick look at the win.ini file because XP, Win2K, and NT use this file, and some third-party applications will make entries in this file when they install. Often, systems administrators use System Configuration Editor during the diagnostic process when they attempt to determine whether a new application has damaged their system configuration.

Administrators who have experience with the basic OS files are likely familiar with the many tricks for editing the system startup files. For example, Microsoft provides numerous diagnostic configuration options that you can add to the OS boot definition in the boot.ini file. Administrators often use the Control Panel Services applet to disable services that they believe might be causing system problems or that they need to stop for some other system maintenance activity. And by now, of course, almost every Windows user is familiar with the safe boot menu that appears after an unexpected shutdown in later versions of Win9x or when you use the F8 key during the Windows system boot process. One of the options on this menu lets you watch the system files load; if your computer is hanging or crashing during the boot sequence, by watching the files as they load, you can note which one is loading when the system crashes, reboots, or hangs. Various registry keys control which applications load at start-up. (See the Tip, "Applications Launching Themselves at Start-Up," in the RESOURCES section of the May 2, 2002, Windows Client UPDATE for details about these keys.)

To simplify editing and managing startup options and system diagnostics, XP includes a new application, the System Configuration Utility, which you launch by entering "MSCONFIG" (don't type the quotation marks) at the Run command prompt. The System Configuration Utility lets you permanently edit the system.ini, win.ini, and boot.ini files or disable individual lines in those files. You can also change the order in which the entries execute; doing so can often solve system problems.

In addition, the System Configuration Utility lets you individually disable individual services that execute at start-up, and XP gives you the option to hide the services that Microsoft provides with the base OS, so you don't have to worry about those services in your diagnostic process (not that a corrupted file in one of these services can't occasionally cause system problems). The System Configuration Utility also lets you examine, modify, and disable the registry keys that the startup process uses. Furthermore, you have the option to determine how the system boots up—by choosing between Normal Startup, which loads all devices and services; Diagnostic Startup, which loads basic devices and services only; and Selective Startup, which lets you choose whether to load system.ini files, win.ini files, services, or startup items.

The System Configuration Utility is very easy to use and to understand; it certainly beats trying to play around with individual files and services and the various applications that let you modify them, which makes me wonder why Microsoft hasn't publicized it more. Check out this versatile tool, and let me know what you think.