Export Data on new Sheet with same Id of that column

First of all let me tell you all that i am totally new to Excel. I never used it before.. I am in a little trouble, so i need help of your guyz... Hope you guyz will help me.

My Problem is :

I have two columns "Sr.No" and "Previous Posting" as showing in the image1 (Current Situation).
Sr.No columns contains numbers in series and "Previous posting" contains all the posting details in the same column but in different rows..

Now i want to save all these posting details in a new sheet but not in a single column. Every posting detail should be in a new row with same Serial Number which belongs to that column, rather than all the posting record in a single column.

Results should be like as showing in image 2:

I hope you will understand my question and suggest me how to do this as i am totally new.

Result