External Hard Drive no longer recognized

My HP Pavilion dv7-4065cx laptop no longer recognizes the external hard drive.

It worked fine until the internal drive died and I had to replace it.

The first time I hooked up the external drive after the new internal was up and running, a message appeared acknowledging the external drive and said that something needed changing to make it run faster. It also said that it would make the change in a few seconds unless I told it to stop.

Who doesn’t want a faster drive? I let it run.

Now I cannot access the drive at all.

It appears in “Device Manager” but not in “Computer.”

I have been searching and searching for an answer. I tried changing the drive letter from “H” to “G” but ended up with both “H” and “G” as its name.

There is probably a simple solution to this problem. However, with my luck, I might do something terribly wrong if I keep on fiddling around with this thing.

Any help would be appreciated.

It shows up in DEVICE MANAGER with no question mark.

Checking the driver, I uninstalled and reinstalled the drivers. Upon completion, the message popped up asking if I wanted to Open Folder to View Using Windows Explorer’

I clicked and the message disappeared but I still cannot view the contents of the drive.

same problem for me. buffalo 1 tb hard disk not showing in my computer. its showing in device manage. disk manager is not opening. what to do?

Is Disk1 the new Hard drive you installed WIn7 upon?

And is Disk0 the old Win7 HD which is no longer being used? If not then I would unplug it, swap its cable to the new HD so it becomes Disk0.

In the new Win7 install enable Automatically deliver drivers via Windows Update (Step 3),
check for Windows Updates, then install all Important and Optional Windows Updates to make sure you have all of your drivers and critical patches.

Now plug in the external and watch for activity in your System Tray. Does it install a driver? It needs the WD SES Device driver shown in error in the Device Manager picture above. It should load automatically once you have enabled for this and your system is fully updated and patched.

Wow, Greg! That was a fast reply.

Yes, Disk 1 is the one on which C drive is installed. It is inside my laptop.

And yes, occupying Disk 0 is an backup drive I have used for years - it contains all of my old backup information that I refer to often. It is external and connected by an E-SATA cable.

I did not reconnect it to the laptop until about two weeks after I had installed and updated the new internal drive in the laptop. Shortly after reconnecting it, a message popped up asking if I wanted to make the external drive run faster. It gave me about 10 seconds to stop the process, or it was going to do it automatically. In that short countdown period, I thought “Why not - faster is better, isn’t it?

And that is when my trouble started. I never could access it after that.

Not being a computer whiz like you, I’ll have to think my way through what you just told several times before I will be brave enough to do it.

But, now, I do realize that the wrong disk is being called drive 0.

I’ll be out of town most of this weekend, but I’ll get to it ASAP.

I thank you for helping me on this. I feel sure that you have this problem already solved in your mind.

LA Fred

It looks like DISK0 once had a Win7 install on it. Nothing shows it is an external HD. It's rare one will show up in DISK0, which would be better to have as the OS. But that is determined by which port on the mobo the drive is plugged into.

But if DISK0 no longer has an OS then it should not be marked Active at all. So I would mark it Inactive at the minimum: Partition - Mark as Inactive - Windows 7 Forums

Even better would be to move the data off temporarily and wipe it with Diskpart Clean Command
to clear the external HD of boot code from the old install, then repartition it as a Logical drive: Partition / Extended : Logical Drives - Windows 7 Forums. As a Logical drive it cannot be marked Active or in any other way interfere with Win7 which makes it ideal for data.