I'm running windows 7 64 ultimate on my ssd using daz windows loader for years now. I also purchased windows 8 back in the day of release and have a valid product id for that which i was dual booting 7 and 8 ....8 being on my secondary spinner drive, but 7 on my ssd has always been my primary. I t seems if I do the legit free upgrade its gonna over write 7 on my ssd and replace it... don't want that. So I downloaded the iso 64 windows 10 pro from Microsoft so I could do a clean install on my spinner. First I did put in my product for windows 8 wouldn't take, then tried the windows 7 ultimate key which was generated from daz windows loader....no go.... tryed once again with another fresh install and by passed al the key prompts and still get the error code 0xc004c003 and wants me to put in a valid key. So based on all my research it looks like if I want the legit upgrade free upgrade I have to let this install itself over my primary 7 ultimate....no way gotta keep 7 as primary o/s. Lost and have major headache reading all the posts in the forums trying to figure this one out....any ideas ?