External Enclosure and Halting OS

OS: Windows XP pro SP2,
Athlon 64 and and Asus CSM board,

The enclosure uses SATA , connected directly to my computer, and using an external power supply. I'd like to know what is the "correct way" to connect it?
I connected it like USB external enclosure and it used to work normally.

But recently, when I turned it on, it took very long to access.
I've checked device manager, the drive was detected right away after power on,
but I just cannot view or change the content inside. Every action can takes a few minutes or even longer.
It can freeze the computer completely which even Ctrl+alt+del did not response.
But when I checked the task manager, no process was occupying the resources.

I did a chkdsk, which found only some minor errors and were fixed already.
It does not seems like a disk error to me anyway.
I also rolled back the OS using an image after a fresh install.

What is the problem?

Any advice welcomed,
Thanks

 

Well, that certainly is original: what is, in effect, an internal HDD using an external power supply.
Since you could not easily connect it to any other PC (as you were able to when the external enclosure was connected by USB) was there any reason why you didn't just mount the drive itself internally in the PC, using the PC's own power supply?
Yet the drive worked satisfactorily for some time in its current configuration?
If so, and if checkdisk detected only "minor" errors, I'd still suspect that the drive was starting to fail.
Just my two penn'orth - hope someone else can come up with a more optimistic diagnosis.

 

hmm, I am using the power supply that came with the enclosure
The enclosure has interfaces of internal: SATA and external SATA as well

The HDD is a backup drive, I don't want to turn it on for long so I use external enclosure with independent power. I only turn it on while moving files to backup like a few times a month. It's rather new. That's why I guess it's not likely to be the HDD problem.
As an additional note, I tried to turn the drive on before I boot up which will result in halting the windows startup.

 

Apologies, I misunderstood - you're using an eSATA cable to connect to a corresponding type of port on your PC.

 

Sorry for replying late
I've checked the plug , it's not eSATA but a SATA connector which can be plugged directly onto the motherbaord.
I guess this sort of enclosure require you to restart the OS everytime when it turns on.
But I'm not sure. Hope that anyone can confirm it or correct me if I'm wrong.