Hi Efraim,
I have tried booting up in safe mode (No Wifi /Networking option) and running the system file checker (SCANNOW Option).
No errors were found. I also remember running various scans during earlier investigations (In normal mode), one which lasted several hours which also returned nothing. When attempting to power down or restart from safe mode however, the PC freezes just after
the blue screen appears and the white dots start to rotate. A forced power down is therefore required.
I then attempted a Clean Boot while logged on as normal. There is only one logon account and I am administrator. For the clean boot, all non-Microsoft services were disabled as were all start up programs via the task manager. Problem was still there. After
another boot-up I restored
the start up programs and all non Microsoft services. Problem still remains.
At this point I'll re-cap on the symptoms just in case it helps to re-focus.
On shut-down my display reasonably quickly goes black.
The hard drive can briefly be heard stepping around performing actions then stops.
The only noise thereafter is the sound of internal fan(s).
Its very like its gone into sleep mode but it is not possible wake the computer by pressing a key or giving the on-off switch a quick press.
There is a small white light on my display which indicates that power is on.
This can only be extinguished by depressing the power switch for around 5 seconds.
(I have also tried leaving it disconnected from the mains supply over night)
On re-boot, there is some minor activity heard coming from the hard drive, (not much at all) followed by a delay of around one minute before the manufacturers logo (HP) appearing. This is then followed by a delay of around 3 to 4 minutes before the hard
drive can be heard bursting into life. Blue screen appears and white dots starts to circle followed shortly after by the logon screen.
If a Restart is initiated, the system shuts down and there is a period of around 14 Seconds where the power indicator remains on before switching off temporarily. Once the boot up starts the process is exactly the same as described above.
My PC is set up in such a fashion that the only restore points I now have are after this problem started happening so its not possible go back to a time when things were "normal" unfortunately.
Thank you for your patience and I look forward to hearing from you again.
Sandy
PS My PC is an All-in-One model so its not possible to disconnect any internal hardware without taking the machine apart.