I am dealing with a very odd problem on a server. We had been having some trouble with a server becoming unresponsive and requiring a hard restart to come back online. I started troubleshooting it and didn't find anything noteworthy in the event logs.
I switched over to Device Manager and saw that all the processors had a yellow triangle and were listed as in Code 19 (Windows cannot start this hardware device because its configuration information (in the registry) is incomplete or damaged. To fix this problem you should uninstall and then reinstall the hardware device. (Code 19))
I did some quick looking around and the general consensus matched the actual error. So following that I proceeded to uninstall and reinstall one core at a time. I got to the last one and did the uninstall. When I went to reinstall the whole server froze and became unresponsive.
After yet another had shutdown, the server came up with 7 processors listed (its a HT enabled quad core) and one "Unknown Device".
Using some prior driver sleuthing experience I got devcon on the machine and got the following results. 7 processors all report as:
Name: Intel(R) Xeon(R) CPU E31230 @ 3.20GHz
Driver is running.
The problem child is reporting as:
Device is currently stopped.
Unfortunately this server is a whitebox, so I don't have any good hardware diagnostics to run against the processor. I checked the driver associated with a working and the malfunctioning processor and they are both the signed CPU.inf.
I have never seen this kind of behavior but it seems to be hardware related. I'm not sure how it can only be one CPU entry, because that implies its either a hyperthreaded core that isn't functioning, or a physical core, whose associated HT core is working properly.
Any advice on hardware diagnostics to check or where to go from here?