Upgraded to Win7 Pro x64 from Home Premium x64 (Anytime Upgrade online), specifically to add second identical physical dual-core Xeon processor. BIOS only shows one CPU in socket 0. Win 7 Pro only shows the 2 original cores.
Per recommendations on a Microsoft forum, I used MSCONFIG and EasyBCD v2.2 to "force" Windows to look for more cores... nada!
Mobo BIOS will not "see" second processor, at all. Only recognizes one in either socket. (I have tried both now.)
Dell docs and forums insist the mobo is dual-socket supported in "Pro" and "Ultimate" versions of Windows.
Replaced mobo and running latest Dell BIOS (A08) to no avail...
Two tubes of thermal paste and two mobo's later and I'm outta patience.