PC isn't detecting second HD partition

Due to a recent MoBo failure on my usual PC, I’ve had to dig out my ancient PC. Fortunately, I back-up all of my files on to a second HD. Unfortunately, my old PC is only detecting the first partition of the “back-up” HD.
The HD is a Maxtor 120gig split into two 60 gig partitions. Both PCs run XP Pro, completly up to date. The PC I’m currently using is at least five years old, an Acer with a P3.
Any help getting to the second partition would be greatly appreciated.

Thanks in advance - DESK

How is this second multi partition backup drive connected to the old PC? USB, direct to IDE connectors? Is the BIOS on the older machine capable of handling that size drive? If connected to IDE cable is it jumpered correctly to match with jumpers on main drive? If you boot to an xp disk does it see the second partition?

Is the partition visable in Disk Management? If so you just need to assign it a drive letter there.