Updating a processor
To install a new microcode update, however, the motherboard BIOS must contain the routines to support the microcode update, which virtually all Pentium Pro and Pentium II BIOSes do have.
Intel documents these bugs and workarounds well for its processors in its processor Specification Update manuals; this manual is available from Intel's Web site.Because the update utility may need to load new code into your BIOS, ensure that any jumper settings on the motherboard are placed in the "enable flash upgrade" position. After running the utility, turn off power to the system and rebootdo not warm bootto ensure that the new update is correctly initialized in the processor.Also ensure that all jumpers, such as any flash upgrade jumpers, and so on, are returned to their normal position.For example, if a system contains a processor with stepping C1 and stepping signature 0x634, the BIOS should contain the microcode update revision 0x33.The processor update utility identifies the processor stepping, signature, and microcode update revision that is currently in use.
In other words, you must ensure that the update matches the processor stepping being used.