USB Hard Drive not recognized.

[ragolia]

I have a usb hard drive (60gb western digital 2.5", Rosewill case) that I use to back up my laptop (Dell Inspiron 1505).  Attaching this usb hard drive to the Dell machine has never been a problem. It has been recognized immediately.  I attempt to attach the usb hard drive to a second computer (Compaq/HP nc6400) and it isn't recognized.  Occasionally on the HP machine I will get the pop-up that usb hardware has failed to install.  Typically, I get no message.  I cannot see the drive in Control/Admin/Computer Management/Drive Management. 

Both machines are running WinXP Pro SP2.  I have full admin rights on both machines.  I typically use a usb cord that plugs into 2 usb ports on the laptops - allowing the drive to draw power from multiple ports as needed although I've run it with the power from a single port as well.  One more bit of information about the HP machine - it does recognize a Sandisk USB flash drive with no difficulty. 

[patio]

Have you tried it on the other machine with the powered hub installed ? ?

Are these the front USB ports ? ?

Some of these are notorious for being underpowered...try the rear ones if this is the case...

[ragolia]

On the Compaq/HP, there are 2 usb ports on the left side of the machine & one on the right side.  I have used the usb y-cord (connects to the 2 usb ports on the left side laptop) as well as trying it connected to only a single usb port.  The results are similar.

[ragolia]

Let me add one more curiousity to the mix.  I have attached this usb hard drive to a desktop machine and it failed to recognize it.  I attached it through a d-link 4 port powered usb hub.  No response at all from the desktop indicating that the hard drive was seen much less installed.