BELIEVE IT or believe it not, there are still some Pentium Pro microprocessors and Pentium IIs in use out there in the real world. Probably quite a lot of them.
What fabulous chips they were.

But the sad fact is that Microsoft and Intel have announced that Windows Server 2003, the latest and greatest Voleware, won't use the massive computing power of the Pentium Pro nor will it support multiple CPUs of the equally fabulous Pentium II.

At install, if you have such systems, you will get a message saying that your multiprocessor configuration is unsupported.

This will no doubt puzzle you until you root around in the Vole's technical burrow, otherwise known as the knowledge base, where you will find this statement, eventually.

"Intel discovered that if you use Pentium Pro and Pentium II processors in computers that have two or more processors, the transaction lookaside buffer may be corrupted. The corruption of the lookaside buffer may cause computer instability, data corruption, or other unpredictable results."

Full Article:
TheInquirer