How To Save Data From Universal App And Transfer It To Different Computer

I'm officially getting the new Surface Book on Monday. All of my personal files & folders (Documents, Pictures, Music, Videos, etc.) are stored in OneDrive, so there's no problem there. However, there's one pesky app whose data I don't know how to save. The popular universal app for Windows 10, Sonic Dash, doesn't make use of cloud sync in Windows 10 (this feature is actually turned on in the iOS and Android versions of the game). This means every time you reinstall the app on any one of your Windows devices, you lose all your progress and have to restart all over again on that device. This means anyone who is getting a new device Monday will have to forfeit all their game progress, missions completed, characters unlocked, rings collected, upgrades purchased, etc. when they get their new device.

(I recently asked Windows Central users to tweet the developers Sonic Dash and ask them to enable cloud backup in Windows 10, either through OneDrive or Facebook, so that your game progress would sync across your devices. I think this is still a great idea, and ask you to tweet @HLGames if you haven't yet. However, it technically won't work in time for my switch to the Surface Book on Monday).

So, I'm wondering how I can manually save my game data and transfer it to my new Surface Book manually. Conceivably, all of the app data should be saved to my current computer somewhere, able to be transferred to a different device somehow. Any ways to preserve my game data and transfer it to my new Surface Book?