Prechod z 32bit WIn7 na 64bit W10 by mal byt mozny, daj si tam svoje legal Win7 a stiahni si Win10 instalacku 64bitovu, a z nej to W10 nainstaluj, malo by to ist, ak mas na to HW (CPU 64bit apod)

P.S. ten tvoj W7 kluc by mal normalne fungovat aj pre Win7 64bit, staci si zohnat spravnu instalacku (spravnu verziu a OEM ak mas OEM apod). Netestoval som to ale pisu to po webe kadetade napr. http://www.com-magazin.de/praxis/windows/von-32-bi t-auf-64-bit-kostenlos-umsteigen-3392.html