Its better to do a fresh install than to upgrade the current install, I ended up with some corruption of the OS that required I do a reinstall after about a year anyway.. Its also WAY faster to install Windows 10, as well as get it up to date. If you want a regular start menu, get a copy of "Classic Shell". Windows 10 is also much more stable.
Note I had problems with windows 10 when it was first released but its come a long way since then.