So it's a different hard disk that you have mounted in your computer? I
assume that you see the drive in Windows Explorer but that when you try
to access it you get an "Access Denied" message. You have to grant
yourself necessary permissions to the drive and files or take ownership
of it.
With XP Home to take ownership you have to boot into Safe Mode:
How to take ownership of a file or folder in Windows XP
http://support.microsoft.com/default.aspx?scid=kb;en-us;308421
You don't have to own the files to have access or control over them, you
only need necessary permissions. Without rebooting into Safe Mode you
can grant yourself necessary permissions to the files with the CACLS
command. You must have Administrative privileges to use the command and
it must be used at the Command Prompt.
This will grant full permissions on all the files and folders on drive
d: to all members of the Administrators group:
cacls c:\ /t /e /g Administrators:f
This will grant full permissions on all the files and folders on drive d
to John Doe:
cacls d:\ /t /e /g "John Doe":f
For help on the command do: cacls /?
http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/cacls.mspx?mfr=true
John