Window Control Back to Main Window

Hi,
Please see scenario and give me solution for it.

1: I logged in a website and click on a link

2: A new window opened and I switch control to that new window

3: I added some data and at the end I click on save and close button only option there.

4: Data saved and new window closed as well. I did not close window with driver.close() method

5: Now I am going back to main window control in not shifting to main window

Please any solution for this problem.

Cheers,
Waqar Ali