Mac users are better off waiting for OS X Yosemite to drop before upgrading to iCloud Drive, but iOS 8-toting Windows users are cleared for takeoff. Apple recently released an upgraded version of iCloud for Windows loaded with iCloud Drive.
To enable the feature, just grab and install iCloud for Windows from Apple's support page. After a reboot, you'll see the option to enable Cloud Drive by marking a check box on the iCloud control panel.
Once that's done, you'll see a new entry for iCloud Drive under Favorites in File Explorer, similar to other cloud storage services like Dropbox and Google Drive.
By default, iCloud Drive comes with three app-specific folders for Keynote, Numbers, and Pages. You can also drag-and-drop files and create folders of your choosing just as with other syncing services.
While it's nice to upgrade early, your iPhone and/or iPad will have to be running iOS 8, released on Wednesday, for iCloud Drive to be of any use on mobile devices.
Apple's answer to Dropbox was first introduced during the company's annual Worldwide Developers Conference (WWDC) in June.
Windows users are the first to get a taste of full iCloud Drive support, as Mac users have to wait for Apple to release OS X Yosemite sometime this fall.