Hard drives disappeared

Hello,

I have Haier PM Laptop with 500 GB external hard.

I have divided the partition into three drives.

some days ago, two partition drive were automatically ejecting. but, now both of those partitions have been disappeared permanently. I am unable to see them any more. even i have tried using disk management but failed. It is only showing one partition having 270 GB memory. remaining volume is not showing.
I request you to please help me in this regard.

DISK 1 is showing 465 GB but its shown partition size is 270 GB. I don't know where is remaining volume.