There are limitations with the TV GO app, only 2 devices can watch TV GO content, and you can't always watch some recordings on your PC but you can watch them on your mobile devices.
From
https://www.virginmedia.com/help/using-tv-go
On the home screen you’ll see telly picks from Live TV and On Demand. Downloads and saved shows are in the Saved folder.
Simply tap on your chosen content to start watching! Remember only two devices can watch TV GO content at the same time. When watching Sky content, only one device can watch at a time.
To customise your list of channels, go to settings and My Channels.
Note: Any show you’re watching for 3 minutes or more will automatically be added to your saved folder to pick up right where you left off.