Techniques, including systems and methods, for providing access to remote computing services are described and suggested herein. In an embodiment, a first computer system provides a key to a user device over a network. The user device provides the received key to a second computer system that uses the key to authenticate the user device. The second computer system executes an operating system for the user device according to instructions received from the user device. Results of execution of the operating system are provided to the user device.