I have Windows 7 Home Premium installed and I want to do a clean install of either Home Premium or Professional from a Digital River download ISO. I have backed up my Cert and Key using the tool found here on the forum, but now I'm not 100% sure what steps to take. I simply want to reformat the HD and install a fresh OS without all the bloatware (Asus UL30) and I'd like to get by without using a Loader just for peace of mind. Can my Cert and Key allow me to pass validation using Professional if I had Home Premium, or am I stuck with the choice of Loader or upgrade purchase? How/when do I restore the Cert and Key files? Do I need to use the Key file to install the OS from the ISO/DVD I made, or how does that work? I'm sorry. I just don't fully understand the Cert/Key/Activation process, even after I read the thread. Why is my Cert number different from the one on the bottom of my computer? What is the easiest way to get validated in W7 Professional using my SLIC? OR is that not possible?