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Bowler · Jul 28, 2011, 12:10 AM

I am using Windows 7 Professional edition with a Seagate USB External hard drive for my backups. When first connected with the USB cord, my computer immediately finds the hard drive and everything works great. After a couple of days or even more, the computer can't find the Hard Drive for my backups. When I click on My computer, it doesn't even show the drive. If I unplug the USB cord and replug it in, Windows finds the drive right away and we are ready to go again. For how many days, I don't know. Kind of frustrating when it decides to lose the drive and my backup is scheduled for that night. Any suggestions?
Note that the drive in question is not my main hard drive but a secondary hard drive.

Scleros · Jul 28, 2011, 06:11 PM

Some things to investigate:

Is drive getting sufficient stable power? External drives usually are single USB port powered, dual USB port powered with a Y cable, or by a power brick that plugs into wall outlet. If computer is left on all the time, plugging both the computer and external drive into the same uninterruptible power supply can eliminate power stability issues.
Is cabling topology correct? USB cables should be high quality shielded cables of minimum length. Cable lengths over 3 or 5 meters depending on USB version or connection through one or more hubs can be problematic.
Is drive running latest available firmware? Check Seagate's website.
Are latest chipset drivers being used for the USB controllers?
Is power management enabled on the computer's USB root hub device that the drive is connected to or on the drive? Check settings for both and then disable to see if it makes any difference.
Drive letter allocation. Are other storage devices being added and removed that might be trying to use the same drive letter?
Other USB devices. Are there other devices connected to the same USB hub and controller that the drive is connected to? If they are removed, does the drive still disconnect?

When the drive disappears from My Computer does it still show up in device manager or disk management?

Bowler · Jul 28, 2011, 09:50 PM

Boy... you have given me a lot to check on. The USB cable is plugged into it's own port and not shared like with a Y connector. The Hard Drive has it's own power supply which is plugged in to the same Belkin UPS. I have 3 hard drives (Internal) which all have the original drive letters assigned to them. The Portable External; drive has always been assigned my "H" drive and as far as I know, has never had to fight for a drive assignment. The USB cable seems to be a good quality cable that was bought from Cyber Guys.

As for latest Seagate software etc, I will have to check that and the other things out over the weekend. I thank you for your interest and I will let youi know what I find

Scleros · Jul 29, 2011, 12:49 AM

Just to clarify for others; the Y adapter I mentioned isn't for sharing. Some port powered drives that require more power than a single port can supply come with a USB Y cable with two plugs to draw power from two ports.

Bowler · Jul 29, 2011, 08:02 AM

I did not know of such an animal. That is just the opposite of what I was thinking. Two inlets from 2 usb ports and one outlet?

Scleros · Jul 29, 2011, 04:36 PM

Originally Posted by Bowler

Two inlets from 2 usb ports and one outlet?

Yes, USB 2.0 ports are limited to a max current of 500 mA. If the device requires more than that it may draw from two ports with a special Y cable that normally ships with the device. The cable would be similar to USB B Male to Two A Male Y-Cable.