My son purchased an HP laptop in 2013 with W 8.0 preinstalled on it running in uefi mode. He updated it to W 8.1 via Windows Store early this year. Yday the HP utility started its updating routine which aborted, the system became unstable. I tried to reimage but it hung and froze the rig, I subsequently tried a full restore with the HP utility (F11 during boot) it grinded during more than an hour, rebooted and rewarded me with an "incomplete restore blah blah" message. I thought it was best to make a clean install (still uefi mode) with a W8.1 ISO. Eveything went fine till I had to validate Windows I can't find any serial on laptop, invoice, box... Is there any legit solution to retrieve a W 8.1 license ?