Hard Drive Suddenly appearing as "Unallocated Space"

I have been running a Dual-Boot Setup of XP Pro and WIN 7 successfully
for some weeks while I get familiar with WIN 7.
Recently I have almost exclusively been booting into WIN 7.
In this D.B. Setup The booted OS appers as Primary Partition on the C:
drive with the non-active OS as "Unallocated Space " on the D: drive.
This all happens on the No.1 Hard Drive.
No2 Hard Drive has been partitioned into several Partitions , the
First one as a Primary Partition with the remaining Partitions as
Logical drives.
Today , when I booted into WIN 7 , there was no sign of the second
hard drive and its Partitions even although both drives ( Serial
Drives) were recognised in the initial part of the Bios screen during
this bootup.
When I looked in Disk Management , I saw that the first Partition on
the second hard drive appeared normally as a Primary Partition but
that all remaing space on this drive was shown as "Unallocated Space"
I then re-booted into the XP OS .
This showed the second hard drive and all its Partitions normally ,
i.e. with its first Partition as the Primary and all subsequent ones
as Logical Drives.

Please post back a screenshot of your full Disk mgmt drive map and listings, using SNipping Tool in Start Menu. Tell us what is on each partition, have both HD's attached.

Do you wish to continue with XP or remove it?