This was first pointed out/reported to Microsoft by MS MVP Cari (apparently MS is looking into this "issue") after information was received from Intel.
The problem of SP2 not installing on Prescott (Celerons) and Extreme Edition CPUs has been identified. The problem appears to be due to the machine's BIOS not installing a production level microcode update.
To check whether the BIOS is at the correct level, download and run the Intel Processor Frequency ID utility
The microcode version is identified by this utility as "CPU Revision". So for this CPU:
* CPU Family = 15
* CPU Model = 3
* CPU Stepping = 4
The microcode revision should be at least 8 (if it is zero, then no microcode update was installed at all):
* CPU Revision = 8
If the microcode revision is not 8, then boot into Safe Mode. Rename the file %windir%\system32\drivers\update.sys so that it does not load. Apply the SP2 upgrade file and the machine should boot properly.
Frequently check the website of your motherboard manufacturer for BIOS updates as the above is a temporary workaround and may cause instability....the machine may be unstable until a new BIOS is installed and update.sys is put back into place and thus able to load the most current microcode update.
Not all Intel processors are capable of the frequency test feature of the utility. See the supported processors list for details.
Listing of motherboards known, thus far, to to present the problem:
Abit IS7-V
Albatron PX865 PE Pro
Aopen AX4SG Max
Aopen EA65
Asus P4P800-E deluxe
Asus T2-P
Foxconn 865A01-G-6EKRS
Jetway i875P
Shuttle SB61G2
Soyo P4I865P
If SP2 has already been installed, and system fails to boot, here is
a reported workaround:
Since this is apparently a mainboard BIOS and L1/L2 cache issue, enter mainboard BIOS and "disable" L1/L2 cache, then enter system and uninstall SP2. SP2 will be listed in add/remove programs if you updated an existing Windows installation, if this was a fresh install w/slipstreamed CD then you should hurry and update BIOS as performance is affected without L1/L2 caches.
NOW..
go to mainboard manufacturers website and update the mainboard BIOS to latest one (Prescott users)
Then you can re-enable the L1/L2 processor/mainboard(?) caching, and install SP2 properly (that is.. if mainboard people updated their BIOS code)