How can I set only two vsplitted windows in VIM/NERDTree?

Question

The left side window will be the NERDTree tree-like menu and if I type "s" on any filename it will be opened at the right side window as vsplited.

Now if I press "s" again on any file from the left side tree-like menu that file will be opened at the right side window as splited window but the previous window will be replaced or the previous window will be closed.

How can I do this?

Answer 1

When you are on the window you wish to repace (the right one) you can press Ctrl + w twice to move to NERDTree. If you then press o then NERDtree will open the file into the previously used window (the last one).