How do I re-open the Visual Studio Immediate Window?

If you can not see Immediate Window In Debug -> Windows menu:

1. From the menu bar, go to View > Other Windows > Command Window
2. Type and execute immed command

To get the immediate window back you can go to Debug --> Windows --> Immediate or you can use CtrlAltI either will work to get it back.

In addition to what previously was mentioned by @sansa and @Mark Hall, you can also use Quick Launch:

• Press Ctrl + Q to focus on Quick Launch text box.
• Type Immediate then choose the item that appears: Debug -> Windows -> Immediate(Ctrl+Alt+I)

Update: For more information on Quick Launch you can check it here