So i built a gaming pc,but totally forgot about the OS.Luckily,i found a windows 7 disk lying around,but it's not genuine.If i buy a windows 7 activation key,and activate it on this pirated win 7,will i get the free upgrade?Cause i seriously don't want to reinstall all my games which are 500gb in all,all over again.If not,i'll get an external hard drive,but it would take ages to move them.