Tony
In that case it may well be the Adobe Shockwave player he needs. Thats used a lot in instructional videos
Get them to install Flash and Shockwave
https://www.adobe.com/go/EN_US-H-GET-FLASH
https://www.adobe.com/go/EN_US-H-GET-SHOCKWAVE Download these from within Firefox as Adobe have different version for FF and IE, and the version you get depends on the browser you use to download
DON'T install Realplayer and Flash on the same machine - they don't work well together. The video download option which Realplayer installs makes the Flash player unstable