Will not 100% power off after fresh install of Win 7 OS.

I know there are many posts about PCs having the power supply still supplying power after you have done a Start/Power/Shutdown. I've looked over many of those and they give suggestions related to a system that has been in operation for a while. With possible causes like PSU, hardware or motherboard issues. But none of that applies here. This has got to be a setting I'm overlooking that is related to how Windows 7 shuts down.

What I'm looking for are what settings would prevent the OS from sending the shutdown command/signal to the power supply? The following is how I got to this state.

Background:
Started out with Customer's PC being painfully slow, (HP 5-6 year old dual core Intel). It recently migrated to Windows 10, which the customers did not like at all. I suspected the Hard Drive based on the age of the PC. The S.M.A.R.T data on the Hard drive showed tens of thousands of read errors. It was agreed to replace the hard drive and do a fresh install of Windows 7 home edition 64 bit and transfer the user data to the new setup.

Leading to the problem:
During the Win 7 installation I had to change the BIOS settings for SATA to emulate IDE so the drive could be found by the OS. (Note: At this point and after installing chipset drivers I still have to keep the BIOS in IDE mode. If set to AHCI boot up fails.) At this point, before OS updates, shut downs and restarts were working fine. After getting ALL the OS updates I thought I was done. (Note: I did change the settings so the PC would not go to sleep due to no user activity. It had done that during the updates, which moving the mouse or tapping keys did not wake it up. I had to cycle power.) I did a shutdown through Start/Shutdown and it behaved like a normal shutdown but all the lights and fans kept running. If you press and hold the power button it would shutdown completely like it should have. So that eliminates button issues.

Possible causes I troubleshot:
I noticed it had a WiFi card in it, and remembered hearing how sometimes it keeps the PC active for restarts from a signal during shutdowns, I removed the card. (Note: I did not see a diver for it in the Device Manager for me to change settings.) No change. I tried a different power supply to see if that changed anything and still had the same behavior. Replacing the MB is not an option, besides, it would shutdown ok before I started.

My suspensions:
I'm thinking I'm overlooking something simple in the settings for shutdown. What really puzzles me is I've done many rebuilds like this before and it all worked fine in the end. This is the first time I've come across this shutdown issue. I have not yet done a BIOS reset to factory, IE: pull the battery.

Apology for the long post:
I may have gone overboard on the above. But I often see posts where the complete story was not told and time was wasted with answers that the poster had already tired.

Thank you in advance for your advice.





PS. I had to do this a second time cause I took too long to write it and got timed out.