Change its appearance theme to the windows one (in the settings app), disable the bottom bar/dock and move the top bar down to the bottom. Now you've got a typical windows style start menu. XFCE is very flexible and you can configure the docks/bars to feel like old windows, old Mac, etc. Its file manager (thunar) is basically a a perfect copy of Windows file explorer from the XP era.

If you want to go full old windows it's an easy next step to run this theme's setup script: https://github.com/grassmunk/Chicago95