Join the “Bing Rewards” initiative: it is like a frequent flyer initiative, but now to get points you have to navigate with the Bing search engine, not with a plane!
Last week it was an initiative only for United States users: I read that now it is extended to other countries (Italy included) so the procedure should be much easier. However I didn’t succede without installing, for example, the Hola browser extension (e.g. in Chrome), and choose United States from the upper right icon, to let my browser be seen as it was working in that other Country. Therefore, if you have still problems “because your Country is not yet included in the Bing Rewards“, do the same I did 😉
So, (maybe after have set the United States in your Hola browser extension) you only have to go to this page an accept the conditions related to the “preview.onedrive.com”:
Then you have to select the “Free storage” section to claim the free 100GB of OneDrive for 2 years:
Note that after the two years of free subscription, if you have stored your data in some of that free space, the size will be set to the maximum used space (no data will be deleted) but you will not be able to store any more data in OneDrive still you have decreased the used space to the one you have without that promotion (or buyed with some subscription).
PS – Remember to have also a look to the access rights you gave to some apps, related to the access of you personal data included the one you put in OneDrive: https://account.live.com/consent/Manage