USB External HD problem

I have a Sony Vaio VGN-FZ210CE. My issue is that when I use my external hard drive, it works when I first start it up but then after a lil while (tonight it went around 10 minutes), it suddenly says it isn't recognizes & then goes on to install the driver & then it will work again. It's annoying, especially if I happen to be in the middle of something. The first few times I used it, it didn't do this, but it has now for quite a while.

There have been no issues with the hard drive when it's been connected to my desktop (which is slowly dying of old age). There aren't issues with my wireless mouse, flash drives, printer, or scanner. I have tried using different ports, they all do this with this device.

I tried uninstalling the usb drives through the device manager which instantly reinstalled & I even restarted the computer anyway. I had emailed Sony about the issue once & was told to uninstall the drives but lost the email somehow so I don't know if I did it the way they suggested.

Does anyone have any suggestions for me, something I can try?

Thanks for reading my long post & I appreciate suggestions!

 

Is your USB drive powered by USB or by separate power adapter? Is it connected directly to USB port in laptop or through a hub? If it's powered by USB, is it a single cable (may not be enough power and periodically reset connection) or is it split/dual (two USB heads data+power plugged into laptop)? If it's powered by a separate power adapter make sure that is plugged in into a stabilized power source. Laptop is stabilized by its battery, fluctuations in power outlet may lead to voltage differentiation between laptop USB and drive USB and cause connection reset.
Desktop USB usually can provide more power than laptop USB when external drive is powered by USB.

 

It is powered by a separate adapter. It is connected directly to the laptop.

I have plugged the adapter into more than area & it had problems in both. The laptop itself has usually been plugged in at the time, never tried using the HD when the battery was low.

Thanks for your suggestions tho!

 

FZ issue maybe? I noticed that problem too, specially today and finally had to copy all project files to internal, I checked 3 different USB cables, also Firewire (the external has both) It was happening before with 2.5 USB HDs but I thought it is power issue, seems like something else,since same happens with PSU powered 3.5 HD, but whatcould it be? I have all my USB ports set to no power save modi, after reading above post started to suspect FZ, SZ has no issues like that with all those external HDs.