After a little failure on my PC (unable to go on the web, despite a good connection), I did as any dummy: I restored the system.

Windows 8 or 7, no difference (I hope Win 10 won't change our habits). Now all is ok but, after that incident, I thought I had to change the parameters of the restoration. And surprise, two unpleasant anomalies:

1 - Impossible to install the points of restoration on D:, my biggest drive. I always try to save any Gigabyte of my little SSD C:!

2 - The micro SD card E: is invisible in "Restore". Impossible to use it for that.

No problem, the points of restorations are always in C:, 45 Megabytes every point, not a drama, but annoying.

I know, I must buy another computer.

Yes you are correct GT, the restore files are always on C: drive, in a hidden folder too, It would be a good idea to be able to have them on another drive, at least give us the option to move them if we want to.

Gets my vote 

Thanks Data, end of the mystery. I thought something wrong happened in my PC (or in my Windows).

Maybe some people who are testing W10 could suggest that little problem to Microsoft.

Mine is that, when C: will be nearly full, I shall have to get rid of my greedy apps (mainly, car and plane simulations). But I guess I will survive.