New
#11
Well, in case you want to revert than don't. If you have enough space for now you can keep it until you are sure, it will be deleted automatically in 30 days. It's clearly largest part, contains most of your past installation and that's why it's so large. How much free space do you have ? Need at least 10% or 10 GB free for proper windows function.
If i revert back to Window 7, can i come back to window 10 again?
Yes you can as long as it is on the same system you activated 10 on. The focus is on MB, no other parts matter. No hurry though, you have a month from date of upgrade to do it. Actually you can go back to W7 even after that but would have to do clean install.