portable 2.5" HDD not detected

hi guys, need serious help. my portable HDD works in all my laptops and other desktop PC except for the new desktop PC i just assembled. it's running on W7 32bits. everytime i plug it in windows installs it "initio default controller" making it unusable (can see in devive manager as initio default controller). i've disabled it and uninstall but when i plug my portable HDD again it again install "initio default controller". i've tried to update but windows says "initio..." is the latest. all my thumbdrives, usb mouse and keyboard works properly, including my usb speaker.
any help would be highly appreciated.

Sometimes there are different controllers internally in the case for the external HDD.

How long have you left the HDD connected to the desktop? Sometimes it may take up to a minute or so. Usually it's faster than that but sometimes it will lag.

HDs require a lot of power.

Make sure you are using a high quality USB cable. The original should be OK but cheap replacements can cause problems.

If you are trying to use a USB hub this can often cause problems (if it is a powered hub you should make sure it is plugged in). But best is to try plugging it directly into a USB slot on the back of your computer.

Also you want to go to the HD manufacturers site and make sure you have installed the latest firmware for their product.

After trying the above, if it is still a problem you might try Microsoft's Mr Fixit for USB devices.

i did some research before posting my problem here. i've already tried plugging it in all the usb port (front and back) of my new desktop pc. i dont suspect the cable as well as all of these portable hard disk works on all my home laptops and even in my work desktops. except in this new desktop, they are immediately detected in my laptop and work desktop. i have also installed the inf and all drivers from my motherboards driver cd. the only option i do now (until this issue is resolved) is use my thumbdrive to transfer files to and from this desktop pc. thanks for your suggestions, hope to get some more until this is fixed.

After you plug it into your desktop, are you able to see the drive under the drives section in Computer Management?

This probably won't help with this problem, but always get the latest drivers from your motherboard maker's website. Any drivers on the CD can be extremely out of date or even buggy early versions.

i am not able to see them device manager, except for "initio device controller" which shows up whenever they are plugged in. i have already installed the latest drivers which i downloaded from the net.
NOTE: i just found out that my WD 1TB is able to use for this desktop. So, only my hitachi 320GB and 750 toshiba portable HDD are unusable in this desktop. i did a check for any drivers for these HDD but i found none.
Once again, thanks for the suggestion.

As I mentioned before, you should make sure the latest firmware for those hard drives is installed in them. Use a laptop or desktop where they ARE recognized to perform the updates, then see if they are recognized on the new machine.

I suggest you contact hitachi & toshiba, as they are responsible for providing the drivers for their products. It is much more likely someone can help with this on their support and/or forums.

i went to toshiba and hitachi's website and they mentioned that there is no need for any driver for these portable HDD. i will try to send them an email about my issue. thanks