Hi all ! I have just face a problem that I wanted to install Linux on my system, and I emptied one drive completely and deleted it using Computer Management Console. But deleting this partition caused unstable hard disk. Like one more partition got deleted on its own. The partition I deleted was PRIMARY partition and the other partition I have lost is extended partition. Now I am having free space 30 GB unallocated, 523GB free space,672GB unknown healthy partition.Originally I have 160GB(Seagate) + 40GB(Samsung) hard disk space. Screenshot is attached: Can somebody recognize the problem and suggest me how to recover the lost partition ? Thanks in advance.