Need a spare computer to test something for 2 minutes but (obviously) you cant justify the expense?
Turn on Windows Sandbox to quickly spin up a temporary windows virtual machine that whatever you do there will be deleted once you close it.
Want to check a suspicious link in a email, open it in sandbox
Want to check what some code will do, run it in sandbox
No keeping it up to date, no having to get a second machine to test.
Just check it and continue on with your work.