Is there a limitations to the number of cores on Windows 7 64 operating system?

Solution 1:

According to this information provided by Microsoft, it depends on the version of 7:

http://windows.microsoft.com/en-US/windows7/products/system-requirements

I would quote, but phone copy/paste with chrome is not cooperative. Supposedly any 32 bit 7 edition will support 32 cores. Any 64 bit 7 edition will support 256 cores.

Further, the maximum physical processor count recognized depends on the edition. Starter and any Home version support only one physical processor per system. Professional, enterprise, and ultimate support no more than two, so without going to a server edition, your system won't recognize or make use of the additional processors. It also may be difficult to find 7 motherhood drivers that would let you even load/install to a 4 processor board.

It is not spelled out explicitly from this article, but I believe that this is the cumulative core limit across all physical processor count in a system with the exception to the Windows high performance computing (hpc) build, which isn't really a 7 edition but instead a server edition.

Solution 2:

JustinC already linked to the document I am referring to: Keep in mind that there is a physical CPU limit of 2 with Windows 7 Professional, Ultimate and Enterprise.

You are planning to use 4 processors, this will not work.