I have a new Toshiba X75 laptop running Windows 8.1 64 Bit. One of my external drives keeps disappearing on me and the only way that I know of to get it back is to reboot, and this is getting old real fast.

I have 5 external hard drives; drive 1: 500Gb, USB 2.0 western digital, drive 2: 2TB, USB 3.0 seagate, drive 3: 3TB, USB 3.0 seagate, drive 4: 4TB, USB 3.0 seagate, and drive 5: 4TB, USB 3.0 seagate. Drives 1, 2 & 5 are connected to a powered USB 2.0 7 port hub which is plugged into one of the laptop's 4 USB 3.0 ports; the othe two drives are plugged directly into two of the other three USB 3.0 ports on the laptop.

Drive 1 has done this once before and hasn't done it since. Drive 4 is the problem child although drive 5 has done this in the past too. Both drive 4 & 5 where purchased at the same time. At first I thought that drive 4's problem was the drive it self, so I had it replaced, but it still is a problem child. When it was replaced they gave me a newer version of the drive too.

Is there a fix via Microsoft?

I have read that there might be some sort of a fix for the registry, but when it comes to playing with the registry, I tend to make sure that I know exactly what I'm doing before hand, and right now I don't know what to do in the regestry.

Anyone have some great ideas? 

And thanks ahead of time for the help.

Does same HDD works fine on other systems ? Just to verify that its not something related to bad/damaged port/cable. 

Yes they do, so, yes the cables work fine.

This is probably the article that you were referring to with the registry fix:

"Help! After installing Windows 8.1, my USB drive disappears or file transfers stop unexpectedly..."

This article was updated to state that the registry workaround is no longer required, as the Update has a fix in it. However, you still might want to check the power settings and make sure 'suspend' is disabled.

Hope this helps,

David
Windows Outreach Team - IT Pro
The Springboard Series on TechNet

Yes, I just made sure that they were not enabled. I'm waiting for a download to finish and then I will reboot and wait and see if that fixed it. I will advise later.

Just wondering how come just the one external drive is always doing this and not any of the others (lately)?