When your run Windows NT Diagnostics (%SystemRoot%\System32\WINMSD.EXE), or the System Information tool in W2K (%CommonProgramFiles%\Microsoft Shared\MSInfo\MSInfo32.exe), and view your CPU speed on the System object, your CPU spped may be incorrectly reported.
If you have a 266 MHz Intel Pentium-II, it may be displayed as x86 Family 6 Model 3 Stepping 4 GenuineIntel ~264 MHz".
NOTE: The Tilde (~) means: approximately.
This is just a bug in the above mentioned programs, as is not any cause for alarm.
The 1st time I ran the the System Information tool in W2K, on my 450MHz laptop, it reported 4MHz, but subsequent initiations worked correctly.
NOTE: Microsoft is aware of the problem.