I have a Western Digitial 1TB 10eavs ext USB HDD. I am currently running Windows XP Sp1,

(no I have hardware issues with SP2 and it gives the vaio mxs10 the BSOD with no OS... but that is a totally different issue... back to the point.)

I have slow USB port speed, (no high speed ports.)
The HDD is fine, used it with many other PCs and no problems, I can even run it on a vista right now, but I want to use it on my xp.

Now the issue... It seems that it is a common issue for winxp not to recognize the ext HDD of WD. Well more that it fails to assign a drive letter.The fact that the HDD only work with plug n play drivers, means that reinstalling the driver is to take it off, and unplug and plug it back in.

Sometimes, I think it is assigning a drive letter, but something is impeding the functionality on the "my computer" to display it, and the disk management just freezes up... you can tell that it is transferring information to and from the HDD but nothing in "my computer".

I have used powertoys Tweak UI to fix the auto play issue.
and seldomly if I plug it in while the computer starts up (while it runs checkdisk) I can get it to properly show up and run just as if it was a normal usb HDD on a vista. But the moment I restart or unplug it, it's the same fight.

My question is...

In the bios there is an option for setting an ext HDD as a slave, primary or secondary. I would like to know if setting the drive as a primary or secondary slave is going to corrupt the information I already have on the ext HDD or mess up my windows OS?
I would rather not ruin what I already have on my ext HDD if at all possible.

IT freezes up the PC when I plug it in...occasionally, like the amount of memory is stifling it or something, but the CPU is around 20% 40%, and "My computer freezes" so does "TweakUI" and "MMC.exe Disk management"

Don't know this particular hard drive, but it strange you need a driver for it in Windows XP. I have 9 external usb hard drives (from Maxtor, Seagate, IOmega and Western Digital) and have never installed any drivers for it. Used the Maxtors even under Windows 98.

The fact that you BIOS has an option to set the external as slave, primary or secondary sounds like the BIOS is the problem. You can freely play with these settings without disrupting any data on the drive. It is the same when you should have a second internal pata hard drive. (sata drives don't share the cable and are always master).
If you change an older pata drive from master to slave or slave to master the data on it won't change. The only thing is, with one setting you see the drive with the other you don't.

I cannot seem to get the bios to see it as a hdd for slaving.
it seems to reporting it as a USB Device: MY BOOK in the dos startup before windows loads. How should I set the Bios?

Aha, a Western Digital my book model. That should work without drivers in XP. Just plug it in and XP will find the drive assign a drive letter and its ready to use.
In your case however, that doesn't seem to be happening. I can think of a lot of reasons why the drive is not always found, but the most likely is a problem in XP itself.

The HDD is fine, used it with many other PCs and no problems,

Do these machines have XP installed and if so, what version? Do they have usb 2 or slow usb ports?
You could try the drive on another XP machine (with SP 1) and connect it to the slowest available port. If it works without problem, your XP is the culprit.
Don't know what software you have installed but wouldn't be surprised if something is interfering with the detection process. Many times these problems disappear if you run the XP install and let it repair your current installation.

Aha, a Western Digital my book model. That should work without drivers in XP. Just plug it in and XP will find the drive assign a drive letter and its ready to use.
In your case however, that doesn't seem to be happening. I can think of a lot of reasons why the drive is not always found, but the most likely is a problem in XP itself.
Do these machines have XP installed and if so, what version? Do they have usb 2 or slow usb ports?
You could try the drive on another XP machine (with SP 1) and connect it to the slowest available port. If it works without problem, your XP is the culprit.
Don't know what software you have installed but wouldn't be surprised if something is interfering with the detection process. Many times these problems disappear if you run the XP install and let it repair your current installation.

Unfortunately my Xp(home edition) (2002 make) has no service packs installed currently because I just did a full system recovery a few days ago. First thing I did was try again to get that HDD to work. Yes it works with the XP versions at school (w/ sp2 but sp2 give my computer BSOD because of hardware issues conflict with the OS update). and the HDD works With vista.

Yes as I mentioned above that I am using slow USB ports and at times it recognizes the drive... if and when I go through a bunch of complicated steps but the computer won't automatically see it once it reboots after it does recognize the drive.

I used the disk management to assign new letter
I used tweak ui to prevent autoplay, (because that may have interfered) still the same fight.

The person that responded before says that the BIOS might be interfering with it because startup even rejects the drive
in the blk and wht dos screen during boot up.....
Sony....
"press a key to reboot"
I go into the bios (while my book is plugged in) and my master drive (samsung) doesn't show, so I am wondering if this USB device causes the computer not to recognize the master HDD inside of it.... maybe because it's confused over which drive is partitioned with the OS?

With a clean install of XP and still the same fight... how would it be the OS?
when the drive is plugged in from boot up, it won't even allow the computer to get to the OS boot.
"press a key to reboot"
so wouldn't that be the BIOS?
the computer sees it as
"USB DEVICE: MY BOOK<<<<<<(this)
MAster..... Samsung
Primary slave... none
_____?_____(forgot)..... Pioneer blah blah (dvd rw drive)
secondary slave : None"
when listing the devices before you can access the bios, but it says nothing in the BIOS about a USB HDD.

From your latest post I conclude there is a boot order problem in the BIOS. It looks like the usb drive goes before the internal hard drive. You should check the boot order (must be somewhere in the BIOS) and make sure the internal hard drive comes before the usb drive.

As why the usb drive doesn't work properly in XP? Maybe this type of hard disk can't work correctly when connected on a slow usb port. From all my own usb drives only the Maxtors (10 years old 300GB) ever have been connected to slow usb ports. And that was never a problem. According to the WD site it shouldn't be a problem to connect an usb 2 drive at an usb 1.1 port. Except for there usb 3 model.

Is your usb drive by any change an usb 3 model? If it is, you can use it at an usb 2 port but from the WD site:

Note 2: WD recommends against using a USB 3.0 drive on a USB 1.1 hub, switch, or controller.

From your latest post I conclude there is a boot order problem in the BIOS. It looks like the usb drive goes before the internal hard drive. You should check the boot order (must be somewhere in the BIOS) and make sure the internal hard drive comes before the usb drive.

As why the usb drive doesn't work properly in XP? Maybe this type of hard disk can't work correctly when connected on a slow usb port. From all my own usb drives only the Maxtors (10 years old 300GB) ever have been connected to slow usb ports. And that was never a problem. According to the WD site it shouldn't be a problem to connect an usb 2 drive at an usb 1.1 port. Except for there usb 3 model.

Is your usb drive by any change an usb 3 model? If it is, you can use it at an usb 2 port but from the WD site:

The model is USB 2.0.... with mini type A plug that goes into the HDD.
I will try to mess with the boot order and see if this resolves the issue. Thanks