Extensible counters are Performance Monitor counters that don't come with Windows NT. They come with other applications you run on Windows NT, or you can build them yourself with help from the Windows NT Software Developer's Kit. Extensible counters are usually installed when you install the product, but you might need to install them separately. For more information, consult the manuals that come with the product.
Tip
Extensible Counter List (Exctrlst.exe), a tool on the Windows NT Resource Kit 4.0 CD in the Performance Tools group (\PerfTool\CntrTool), lists the extensible counters installed on a computer. It can be used on the local or a remote computer. For more information, see Rktools.hlp.
The Windows NT Resource Kit 4.0 CD provides some extensible counters that must be installed separately (for example, those that monitor Pentium processors). The help files for the Resource Kit CD, Rktools.hlp, explain how to install them, and the "Pentium Counters" section of this chapter describes some common uses.
Regardless of their source, extensible counters must be monitored carefully. Damaged data buffers could damage the operating system. If you use extensible counters, consult "Troubleshooting Features," earlier in this chapter.