Two My Books not detected unless restart

I have a 750 gig My Book and a newer 2 TB My Book, both of which work fine if they are detected by my Windows 7 Lenovo Thinkpad T530. When I power up from off, both drives are detected. If I restart, both drives are detected. But if I put the computer into sleep mode (standby) and disconnect the usb cables to travel, when I wake the computer up neither drive is detected in any of the USB 3 ports or the USB 2.

I have run the USB cables through two different hubs, and directly to the USB ports. I have connected the power bricks directly to wall sockets bypassing surge protectors.

I have tried different USB cables.

I made sure that the computer’s BIOS was updated to the most current version.

I configured properties so that the USB ports won’t power off automatically.

No matter what I do, I can be confident that if I put the computer to sleep, it won’t wake up the My Books when I wake up the computer again. Makes no difference whether I connect the USB cables before or after the computer wakes up. Makes no difference if I try connecting only one of the My Books instead of both of them.

In device manager I found this flag:  “Windows cannot load the device driver for this hardware because a previous instance of the device driver is still in memory. (Code 38)”

Would appreciate a solution.

Welcome to the Community.

That is a driver ID conflict. Windows does not unload the device before you put the computer to sleep, and as such, Windows still believes the device is in the same state as it was before hibernation. However, the hard drive itself lost power and lost the connection / session.

Have you tried safely ejecting your hard drives before sleeping your system? 

The problem occurs even if I safely remove the drives before susending the computer.

How do I force the drivers to unload when disconnecting the hard drives?