Unable to view files from Slave HDD

I Have a Primary HDD 80 Gb and slave 40 GB with winxp sp2. I had had saved all my data on slave HD to avoid any information loss and which also had windows xp loaded. I unable to view my 2nd HDD files. i could see 2 HDD information in BIOAs in hard disk MGMT gives HDD unallocated. when i tried loading only 40 GB HDD as primary it gives System error system Halted. I want to retrieve information frm 40 GB. can anybody help me???