So literally from night to day, my pc just stopped launching any PDF reader. I had Nuance PDF Reader working fine, and had several College pdf files important to me. So yesterday, when i tried to open one of them, it just crashed at launching, saying an error was found and Windows will close it. No explanation. I tried to re-install and found out i couldn't because one specific destiny folder needed Adminsitrator permission (i am admin lol). Anyway, i tried opening it with acrobat and also coudln't. Installed Adobe Reader, X and XI and this time no message showed up. The program starts and then closes itself without any warning or without having opened the file i wanted (i tried many different pdf files). I also tried Foxit, error message at start and crash..
So i went to Google 
it seems other people had this problem, and i tried their sollutions... Repair installation, Re-install, removing Adobe Shockwave, Flash Player and Reader, then install again, running CCleaner, reset pc, latest updates Also tried to run McAfee to check for malwares, and what was my surprise to find that it also crashes at start! It is also adobe right?... Nothing done.
As i said, and as far as i remember, i did nothing different to my pc, only shut it down at night, reboot it in the morning, ignored the Flash Player Update warning because i didn't have internet at the place, and that's all..
I went through several different advices throughout internet and other forums, but it's still not fixed on any pdf reader nor any other user of this pc (only 2 accounts here, both admins). Any different tips?