OK guys... riddle me that...
We're using Acronis Snap Deploy to deploy images to all our computers. Last week one of the maschines disliked its Windows 7 Pro image, right after Starting Windows.... poof reboot, not even secure boot would work.
Installing Win7Pro by hand worked just fine, now that disk wouldn't boot in other maschines of the same type.
Diagnosis said "Everything's fine"... uh, nope, not fine at all.
Luckily we had one week of support left, so I phoned Dell and they sent a technician out today.
The technician confirmed the error and exchanged the mainboard, nope same error...
We then grabbed another maschine of the same type and switched processor and memory around, no change...
The technician then unplugged the io-panel, removed the cmos-battery and plugged the connector in. It booted!!!!
Reconnected the io-panel and the cmos-battery... yep, still boots!
One word summary: HUH?
I mean, that was a brand new mainboard! What was reseted by booting without cmos-battery and io-panel? What's in a power supply? Weird!