If you want to quickly boost your OneDrive storage allocation by a massive 100 GB, simply sign in to OneDrive.
OneDrive of course offers other ways to boost your storage, including downloading the client to your PC and referring friends, but simply signing in seems the easiest way ever.
To take advantage of the deal, sign in to OneDrive.com here.
Update: The giveaway is over now. If you missed 100GB Free OneDrive Storage Giveaway From Microsoft? Don’t worry, Now Microsoft Is Giving 20GB Storage for free. Read about it here.