How to resolve the “processor does not support compareexchange128” error?

Since you see this article, it means that you have tried to install Windows 10 on your computer. Most likely it is very outdated, because the text of the message refers to the lack of support for an important component on the part of the processor. Although this is not always true. It is not always necessary to only change the CPU, sometimes the problem is software in nature. Read on for everything you could find out about the error.

The computer’s processor does not support the important component compareexchange128

The reasons

There is a fairly obvious reason for the error, but it can also be about not quite banal problems.

What is the problem:

• The processor does not support CMPXCHG16b instructions. Instructions such as CMPXCHG16b, PrefetchW and LAHF/SAHF are required to work with Windows 10 x64. The role of the specified component is atomic comparison and exchange of 16-byte values. In simple words, the processor is not able to compare the contents of memory areas with the specified value.
• BIOS settings. Some options in the BIOS, if enabled, can cause these compareexchange128 errors.
• Xeon processor incompatibility with Windows x64. Server processors of older generations are poorly adapted to the user system. The BIOS simply does not have the necessary microcodes for this processor.

How to fix compareexchange128 error?

The first thing you need to do is to check the support for the necessary instructions. It is necessary to study the technical characteristics of the processor for support for compareexchange128 or CMPXCHG16b. Older CPUs do not have this instruction. Although the conclusion is that you need to buy a new processor, we would recommend another way – just install Windows 7 or 8. Simply updating the processor will not lead to much improvement in the overall performance of the PC, since you have an old type of RAM, an outdated video card and motherboard. It is better to buy a new computer in the future. Although if you can find a cheap used CPU with support for the appropriate instructions, it may make sense to replace the processor.

What are the solutions to the compareexchange128 error:

• BIOS setup . You should go to the BIOS and check that the Executable Disable Bits parameter is set to Disable. If it is enabled, disable the setting. After that, the installation of Windows 10 should be successful.

• BIOS installation . As for Xeon processors, you need to flash the BIOS accordingly. Suitable versions can be found at xeon modded bios. Although not all motherboards support flashing. For example, Intel motherboards do not allow this. Another suitable BIOS version can be found at the request: “[MOD] LGA775 Support For LGA771 Xeon CPUs”.

Try the solutions listed above, you might get lucky and manage to get by without the cost. If the problem is in the processor, then it remains only to install the old version of Windows or update. Here it is up to you.