Windows Laptop as Secondary Monitor for Macbook Air (Preferably Wired)
This question already has an accepted answer on stackoveflow: https://stackoverflow.com/questions/11067470/how-to-use-windows-laptop-as-external-monitor-for-macbook-pro

It requires downloading the following software:


MaxiVista on PC
ScreenRecycler (for Mac)


It seems like Maxivista.com has migrated to https://www.sharemouse.com/ (Since MaxiVista has been discontinued and replaced by sharemouse)

Here's a website that still has a version of MaxiVista available: https://maxivista.jaleco.com/