HD failed, 2 different ones EIDE & ATA aren't seen, can I use I/O

It should,

It sounds as if the SMART measurements on your Seagate 320GB hard drive are triggering the Windows message advising that the drive is failing.

You would be best advised to backup your data from this drive to a different drive or on to DVD media (depending on how much data is involved).

To test the failing Seagate disk, download a copy of Hiren's Boot CD which is a CD image file (.ISO) and must be burnt to a blank CD disc - then boot the computer with the failing disk from this CD - then select DOS Programs on the initial menu, then choose Hard Disk Tools and then HDAT2 - this is a tool which will let you try to recover any bad sectors on your boot disk.

On the Hard Disk Tools menu there is also a SMARTUDM - HDD S.M.A.R.T. viewer which will let you examine exactly which areas of the Seagate disk are giving the problem leading to the failure message.

The reason why it is not recognize by the other computer it is because the operating system of your computer is different from dell.

It is IDE. 383486-001HP 80GB Ultra ATA/100 EIDE hard drive - 4,200 RPM, 2.5-inch width, 9.5mm height
Hope this helps,www.PuterCare.com

You should definitely try out if it fits inside the bay first.
The original drive in the M55-S135 has a height of 8mm and the WD1200BEVE is 9.3mm. This is not a big difference and may pose no problem, but you would like to have all covers close properly later, I assume.
Other than the slightly larger physical dimensions, the drive should be fully compatible with the laptop.

Go to either bestbuy.com or compusa.com and look for the hard drive there. The hard drive will be cheaper going thru either of those places. Also check out pricewatch.com cause you can compare prices there. Also go thru google and check out the shopping results of the hard drive your looking for as well.

Lots of places to check and the hard drive will definitely be cheaper then going thru HP.

seems u have an earlier version of xp which does not have the AHCI drivers required under the default setting of the controller
Please follow this
http://support.dell.com/support/topics/global.aspx/support/dsn/document?c=us&cs=19&l=en&s=dhs&dn=1090643

differences of amperage this minor will not make any difference. As long as the System Setup (BIOS) identifies the drive, you should have no problem.

The HD capacity is defined by the bios software in the computer, if HP/Compaq tells you that 80Gb is the maximum capacity, then I think you should believe them, after all they should be the first one interested in selling more high price products, go for the 80Gb is .

Ghost will work for Linux drives too.