I have upgraded my laptop OS from Window 7 to Window 10 when window 10 launched. Now message appear on bottom right corner than please active windows (Go to settings to activate windows). But my window 7 was genuine and it came with my laptop pre installed. Then how come Windows 10 become pirated. I lost my Windows 7 produce key. sticker also not available. now how can I activate my Windows 10 . Microsoft online help center said that they are unable to active your Windows 10 without product key.
My Dell laptop model is Dell Studio 1555.