If you have a genuine dvd for W7, you will probably find that all the drivers are there. I've done fresh installs on a number of laptops, and on completion, no yellow exclamation marks in Device Manager. As long as you have backed up the important files, the install will take about 30mins. You will have to, of course, reinstall any programs that you are using at the mo. as long as you have the disks, or know where to download them from (and have any 'keys'), you should have a clear run!
Surface Pro (2017) vs Surface Pro 4