Thanks for the fast reply kemical!!!If your worried about any files before upgrading then your best bet is to back them up first. Usually your old files can be found after the upgrade in a folder marked Windows.old and these can be extracted if need be but to be on the safe side I'd back up anything you want safe just as a precaution.
This is entirely up to you. You could always try it and if your not happy go back to win 7 but you'll have to be quick..is it worth upgrading to windows 10
Only 30 days! You mean after 30 days you can no longer go back and need to restore a backup image?Also, don't forget you have 30 days to revert back to Windows 7 if you don't like it.
It's up to each person to decide whether to upgrade or not.
As far as Windows 10 formatting the drive, only if you do a clean install. An upgrade leaves all programs and files intact. Still, best to backup important files first. In my case, I imaged my drive first. On my test tablet, I imaged the drive, replaced the drive with a new one, and restored the image to that, then tested.
Also, don't forget you have 30 days to revert back to Windows 7 if you don't like it.