After I rolled out new notebook computers to a group of salespeople in my office, several of them asked why the supposedly identical notebooks reported different CPU speeds. The answer is that Intel's Mobil Processor technology makes dynamic changes to the processor speed as part of its power-conservation scheme. Windows reports the processor speed at the moment you query, rather than the processor's maximum speed capability, or might incorrectly report the processor speed altogether.
My IT people wanted to know how to get the OS to report the maximum speed, rather than the current speed, so that they could get a reliable metric without turning off all power management and disabling the Intel SpeedStep application, which lets users customize high-performance computing. A visit to the Microsoft Knowledge Base turned up several articles (here's one example) that pointed to the msinfo32.dll file as the culprit and reported that a fix is available from Microsoft.
In the course of my investigations, I discovered a document called "Windows 2000 Post-SP2 Hotfixes." I'm aggressive about keeping my company's systems updated: I subscribe to Microsoft's hotfix bulletins, read the relevant newsgroups, and get three or four OS newsletters each day. So you can imagine my surprise when I clicked the link and discovered a list of 565 support articles documenting post-Service Pack 2 (SP2) hotfixes! I had never heard of two-thirds of the problems that the articles covered. After spending a few hours working through the article list, I discovered documentation for several problems that had cropped up in our production and test environments and fixes for two problems we were experiencing. I had to read the articles, though, because the titles didn't always describe the conditions we were seeing.
This list is the most comprehensive collection of fixes I've found on the Microsoft Web site, even though I regularly visit the download, update, and upgrade sites for the Windows NT-derived Microsoft OSs. The fact that 565 post-SP2 problems exist is discouraging, but at least you can find them listed in one location. I recommend you visit the site to see whether any of the problems, some of which are fairly subtle (such as a degraded performance problem we had on a few machines), are affecting you.