Win7 does not recognize External HDD please help!

[kin3tic]

My computer does not recognize one of my external hdds. I am using two 500gb external hdds that are from the same manufacturer and only one of them shows up. I am able to swap between each one and read the data from them but they can't both be connected so there's nothing wrong with the external hdds itself. Code 43 comes up and it's unknown in the devmgmt. This had happened just over night. All I did on my end was simply turn off the two external hdds before going to sleep. I upgraded to win7 x64 about a month ago and have not had problems with my external hdds until today. No problems at all with my other usb related devices. It had worked flawlessly on XP 32bit before I upgraded to Win7 x64. I'm sure my computer is not underpowered(Corsair 750w). My chipset is fully updated. It also only shows one of the hdd in the bios when both are connected.

Quick summary:

- 2 identical hdds on win7 x64 (they are not new and have data on them already)
- only 1 of them is recognized at one time
- all other usb devices work (flash drive, mouse, digital music player, etc..)
- can switch between the two hdds manually and no problems accessing data from each. My computer still remembers which drive letter I assigned them to
- the problem started when I turned them off for the night
- only 1 of them at a time is shown in the bios
- it occasionally hangs on the splash startup screen for asus logo now and have to hard restart when this happens
- code 43

I have tired:
- Uninstalling each USB from devmgmt individually then restarting to let it reinstall each USB driver.
- Simply shutting down and pulling the power cord from my PSU and waiting for a bit before booting up again
- Trying to install the USB drivers from manufactures website
- Updating to latest chipset
- Considering updating my bios. However, I would like to hold off on this for now.

Other info:

- no OC done
- absolutely no problems of this nature when I still had XP on my machine and for the first month with win7

From reading around I would have thought it might be my mobo but I haven't had any problems until now. I can hardly believe simply turning off my hdds for the night did this unless someone explains how something ridiculously like this could happen from turning them off.

Any help would be greatly appreciated and I'll give more information if needed!

 

[kin3tic]

Thanks Joules, However, I had mentioned I did the steps you are suggesting in my OP. This did not work for me.

I have tired: - Uninstalling each USB from devmgmt individually then restarting to let it reinstall each USB driver.

But please, if possible, suggest something else because I still can't seem to find a solution to my problem. To further add, I cannot restore my system as that I have been running win7 for not too long and there has not been a time to make a system restore point.

 

[James Colbert]

How are they connected to your system?

James