I have an xp and i just bought this hdd and when i connect it to my computer is says installed and ready to use, but when I look at my comp its not there and the same when i go to disk management.

What do I do????

What are you doing with it ...?
Probably would need to be formatted-- if you need it to work with Windows.
It still should show up in disc management ...hmm

Does it show up in device manager?

Yes it shows up in Device manager as Usb mass storage device but not in disk management. - I just want to put some movies on it and pictures.

Try this-- use a pic for simplicity...
just go to the file (pick one)
Right-click it
in the menu-- is there a "send-to" option?
select it -- and see if USB mass-storage device is there?

If not try using whatever Photo program you have-- or Windows Picture & Fax Viewer... in the "open with" menu

No its not there. I just get
Compressed
Desktop
My docs
mail rec
cd drive D

Did you try using the Windows Picture Viewer from the "open with" menu ?