SQL Server 2005 won't install on AMD Phenom processors
Over the past couple of days I have spent about 3 hours trying to get SQL Server 2005 installed on a new PC. The basic install process was going well until time to start the service and every time the service would fail. Checking the event log I was able to find this error: Microsoft SQL Server 2005 -- Error 29503. Of course the built in MS help wasn't. 
But I was able to find an old post about SQL 2005 not installing on AMD K6-2 processors because the processors use an instruction set that SQL can't understand.
So I'm not sure exactly what is happening here, but I would assume that we have a similar occurance here.
I used to love AMD, but this really gives me grief. I see that the original issue was probably a problem with MS, but three years later and this is AMD's problem. I'm sure they knew about this instruction set problem and should have tested better to prevent it in the future.