External Hard Drive keeps on showing Autoplay prompt

debugged said:

If you're comfortable backing up and modifying registry -
In regedit look at:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer
If the Explorer key isn't there, look here instead:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
(If the Explorer key isn't there, create it)

In the right pane create the dword "NoDriveTypeAutoRun"
Default value is 91 which is supposed to stop autorun on unknown and network drives, which is default behaviour.
A value of 99 should stop autorun on fixed drives as well.
Or a value of 8 stops autotun for fixed drives only.
In your case, I would try 99, which would cover most of the ways your Windows could be seeing that drive.

Well, that is disabling Autoplay at all, right? I am comfortable with Autoplay turned ON, it's just that I want it to run normal just like before where a pop-up doesn't show upon startup due to the external HDD.

kevindd992002 said:

Well, that is disabling Autoplay at all, right? I am comfortable with Autoplay turned ON, it's just that I want it to run normal just like before where a pop-up doesn't show upon startup due to the external HDD.

No, Autoplay should still work as normal for your USB sticks, CD/DVD, Audio/Video files etc., depending how you set it up for yourself. Don't be put off by the name "NoDriveTypeAutoRun" - it's just the place where you can set policies according to the value you use.
Try a value of 99 and see - you can undo it if no joy. Btw, I've tried all the settings I gave you and they behaved as expected.

Ok then. Btw, I also tried enabling USB legacy support and the same result I hate why it's happening.

All of my drives have a GPT partition, is that related to this issue?

kevindd992002 said:

All of my drives have a GPT partition, is that related to this issue?

I have just a basic understanding of GPT drives. You might find these two Microsoft articles helpful in determining if a GPT is contributing to your problem.

Using GPT Drives

Windows and GPT FAQ

I had the same irritating (and potentially data-damaging) issue of the portable external HDD (IOMEGA Prestige 1TB Portable Superspeed USB3.0 HDD) constantly disconnecting & reconnecting (and thus popping the Windows Autoplay prompt) on my home notebook (Dell XPS L501X).

Interestingly, this issue happened only when the portable HDD was connected to any of the USB3.0 ports on the laptop, it didn't occur when connected to the USB2.0+eSATA combo port, so I understood it is a power cycling issue.

All USB3.0 ports are powered ports, and most of the Windows installations have a the "balanced" power-saving mode ON by default (especially for notebooks/netbooks). Windows tries to turn off the USB3.0 devices to save power. Unfortunately, this happens even when the device has been connected just a few seconds ago.

If you are not keen on using a USB3.0 device on a USB2.0 port, you can change the power plan in Windows, but it is not the ideal solution, see this thread for the solution that should work:

External Hard Drive Constant Auto Play

USB 3 is buggy - it also interferes with 2.4Ghz wireless devices working properly.

Go to Run
Then type "msconfig"
Don't copy the quote symbols
Open the tab "Services"
Don't hide Microsoft Services
Disable "Shell Hardware Detection" (uncheck the box at left)
Disable "WinHTTP Web Proxy Auto-Discovery Service" (uncheck the box at left)
Reboot

This should help