I had purchased Dell Inspiron 15 7559 laptop in Jan 1st week , 2017. After around a month, windows 10 started giving me issues related to password after the anniversary update. It would not let me enter the password and would just reset. Dell support team helped me with system restore and it worked fine for few days. But later the same problem was back and dell support team told me to reinstall windows which I did and same thing kept on repeating and I had to reinstall windows as usual. At times, the BIOS would ask em for system password followed by HDD password followed by admin password which I didnt even set. Made this to work by randomly tapping a key 4 times and then clearing passwords in bios setup. Even tried calling Microsoft and all they did was re-install windows 10. As usual same issues were coming. In the end before sending laptop for repair I started getting BSOD. After I got the laptop back from repair on March 23,2017 where they changed the motherboard and HDD same problems are coming related to password. I tried changing windows to 7 and started getting BSOD, even tried with 8.1 but same result. It even ran diagnostic tests on its own when shutdown(Nothing was connected to the laptop. Not even the power cord).
Is there any way in which I can sort this out because the dell repair center has just made things worse for me? I have already lost my labs and assignments in it. I don't want to waste time on this laptop anymore.