Well, i had been swapping HDD drives between SATA ports, replacing a few with bigger drives, until i was satisfied with the configuration.
Some of the drives -all are brand new WD Golds- became VERY unresponsive, took Windows more than 10 seconds to open any folder on them.
I fixed it.
- Device Manager
- Click View. Make sure:
- "Devices by type", and
- "Show hidden devices" are selected.
- Expand IDE ATA/ATAPI controllers.
- I had two transparent (= hidden) Standard SATA AHCI controllers.
Their Properties said "Currently, this hardware device is not connected to the computer. (Code 45) " - In the list, right-click on each of them ---> Uninstall.
- In top menu select Action ---> Scan for hardware changes.
Let it take its time. - Reboot the PC.