Lost Primary, Active, System drive letter

I have a multi boot system; Win8, Win7, Vista, XP, Linux
While was working in XP I updated a very outdated Marvall Sata driver. I rebooted after as one should after a driver install, and XP would not boot. I moved to Win7 and saw in Windows Explorer that the XP drive was missing. I load Acronis Disk Director 11(ADD) and saw that the partition was still there but has no letter. I tried to use ADD to try and ‘Change Letter’ to the first available P:.
I rebooted as the program wanted and got back to win7. But the drive letter did not appear. I did this twice. I tried to view the partition with WIndows 7 Disk Management program but it just froze when it got to the XP partition.
Any suggestions?
Thanks