Microsoft OneDrive

Microsoft OneDrive (formerly SkyDrive) https://onedrive.live.com/about/en-us/ is available as a free program that emulates a portable flash drive, with 5 GB of free space available. Files and folders can be added to it. Your Windows Live account and password are used to maintain security for OneDrive. Additional password protection for confidential files is recommended.

OneDrive
Once installed, the OneDrive Synch Engine Host program remains loaded in memory and appears as a Windows tray icon. Files are synchronized from your Windows 8 PC’s folder C:UsersUserNameOneDrive (or C:UsersUserNameSkyDrive) up to the Microsoft OneDrive servers. Any additional PCs that have OneDrive installed with your Windows Live account will have access to the same set of files. This is an easy way to back up and share files between PCs.
OneDrive is intended for personal and home use. Microsoft has a separate corporate product – OneDrive for Business: https://onedrive.live.com/about/en-us/business/.

Competitors to this product include:
Google Drive https://www.google.com/intl/en/drive/index.html
Apple iCloud http://www.apple.com/icloud/
Dropbox https://www.dropbox.com/