If you're using a genuine windows 7 or 8/8.1, you can upgrade it directly inside your windows. First, you need to download the correct windows 10 ISO image( depends on your current windows). You can get link in here. Then, you need a program which can open and extract ISO file( I recommend the open source program: 7zip). Third, extract this ISO file to a partition differs from the partition that you suppose to install windows 10 to. Wait a few minutes for it to finish and open up that folder and double click on setup.exe file. From now on, you just have to click OK and next to complete the upgrade process. Good luck.