Your Windows license key for an OEM copy of the Operating System (supplied with a new PC by the manufacturer) should be on a sticker on the bottom of the laptop or the back or side of a desktop PC case. Microsoft does not have your license key. In the absence of a sticker on the PC, you'd need to contact Toshiba to determine where the license key was or if it is embedded in the recovery disc.
I had an Averatec PC with XP long ago where the restore discs were actually a Norton Ghost recovery image set of 3 discs. In the case of Toshiba, that's not likely, but it is possible that the copy of Windows on the Recovery disc recognizes the hardware to allow install and it doesn't require entry of a key.
-steve
_________________
stephen boots Microsoft MVP 2004 - 2020
"Life's always an adventure with computers!"