While installing Windows 10 from the Repair Tools command prompt, I ran clean
command by mistake on the whole disk, so it becomes a single 465GB partition. Previously, it contained four partitions.
How can I recover them with the data intact?
Assuming you haven't made any more writes to the disk, I believe TestDisk should easily be able to fix this for you.
Just in case something goes wrong or if this otherwise does not work, I would advise you first take a raw image of the disk's current state, so you can roll back your changes and not put your data at any more unnecessary risk.
Repair MFT
. From the sound of it, though, even your backup copy could be hosed at this point.
I did it by mistake too. Just use "list volume" in order to see if it is still present, you should see the partition's size but no letter assigned to it. Use "assign" and it will work.