SATA Drive partially recognised by Windows

I’m currently moving to another Windows XP desktop with a better spec on a different AD domain.

My current internal Samsung SATA 500GB drive works fine as one big 500GB drive and currently NTFS.

Plugging the drive into the new Windows XP desktop on a new domain, Windows XP recognises the SATA drive but only the free space. It then gives me the option to format the free space. Does anyone know how I can get the new Windows to recognise the entire drive?

Plugging the SATA drive back in to the old XP machine and it still works as usual.

many thanks,

cornish