Lost drawing after a restore point


Been using Sketchup 2017 for a while. Yesterday we had a power cut and when it came back I had to invoke a system restore point to restore the emails on the PC.

However I now find that all of the drawings I did over the last few days have vanished. These drawings were saved to a different drive and folder to Sketchup and not on the system drive but they appear lost!

I had assumed that system restore would not touch any files especially on another drive - most of my other files are intact after the restore so I don’t understand why the Sketchup files have been lost. Drawings from a few weeks ago are still there.

Anyone got any ideas why this has happened and should I now store the files on a USB stick or something?

Thanks. Dave