They should really try XFCE, it feels extremely similar to old-school windows (95/XP). You can even theme it to look unbelievably similar to old windows. I feel like them installing the latest Xubuntu with XFCE and Firefox with an ad blocker would let that old laptop run for many more years of service. Heck, the latest version of Wine probably runs all their old XP software just fine as-is too.
How does XFCE feel like old windows? To me it looks a lot more like OSX than Windows.
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