After shutting down Windows using "shut down", "sleep" or "restart", the usual screen showing shutdown message appears, then screen goes black, the hard drive turns off (if it's not "restart") and then nothing happens (except BSOD with "DRIVER_POWER_STATE_FAILURE" error appeared 2 times after waiting for 14 minutes or more); the laptop doesn't respond to pressing Caps Lock.
To quote The Big Lebowski: "This is a very complicated cause, Maude... Lots of ins, lots of outs, lots of what-have-yous".
Everything that I know, if you don't mind:
• The problem appeared somewhere at the moment when I installed the new hard drive (HGST 7K1000); probably it appeared a bit earlier, I just don't remember already.
• Removing the new hard drive from the laptop doesn't solve the problem.
• After at one time I made an experiment and left the laptop running (with black screen after Windows shutdown command) while I slept, I woke up to see a BSOD with "DRIVER_POWER_STATE_FAILURE" error; the laptop's cooler was running full-speed, like it's using lots of CPU; I don't know at what point the BSOD appeared, since I was asleep.
• At another time I left the laptop running (with black screen after "restart" command) and after 14 minutes I've noticed the same BSOD with "DRIVER_POWER_STATE_FAILURE" error; the laptop's cooler was running full-speed, like it's using lots of CPU; this time I suppose that the hard drive was powered off, because the S.M.A.R.T. "Unsafe Shutdown Count" value hasn't increased - another hint that the problem has something to do with the hard drive's driver, I think.
• The only new hardware installed were HGST 7K1000 HDD and an optibay; SSD was transferred into optibay and the optical drive was removed.
• The hard drive runs with drivers provided by Windows; HGST website doesn't offer any drivers of its own and says that Windows has all the necessary drivers.
• There are also .sys files by Acronis shown in the device properties of the hard drive.
• After installing the new hard drive, the battery's LED was blinking orange; the problem was fixed by holding the laptop's power button for more than 30 seconds.
• Removing the laptop's battery doesn't fix the problem (I checked it twice).
• I used HDDScan 3.3 to change APM settings of the new hard drive.
• When I boot from another system (Windows 7 Home), the problem doesn't exist.
• When I boot in Safe Mode, the problem doesn't exist (I checked it twice).
• The laptop also suffers from occasional "System Interrupts" problem, when the interrupts are taking lots of CPU; today, as an exception, the laptop did shut down properly after I had to shut it down to fix the "System Interrupts" problem.
• As well as I remember (I might be wrong), one or several times more the laptop did shut down properly since the problem first appeared.
• The laptop fails to shut down in all ways: "shut down", "sleep", "restart"; I'm not using "restart" because of that, since the hard drive isn't powered off properly; if I choose "shut down", the system powers off the hard drive; I haven't tried hibernation, because my system doesn't support it.
• The time when the problem appeared approximately coincided with time when I removed the optical drive and transposed the SSD from hard disk bay into a newly bought optibay.
• I removed the optical drive from laptop while Windows was running, but this isn't supposed to be damaging, as far as I know.
• I didn't find anything relevant/interesting in the Windows System Log (Event Viewer), except for "The following boot-start or system-start driver(s) failed to load: cdrom" error and lots of "The system failed to flush data to the transaction log. Corruption may occur." errors.
• I'm not using Windows Update and I haven't manually installed/updated any drivers recently, but Windows has installed its driver for the new hard drive after it was installed into the laptop - this driver is the main "suspect" (if "DRIVER_POWER_STATE_FAILURE" is the "evidence").
I hope there are enough leads and some detectives are available to work on this case.