Lenovo recommends Windows.

* Lenovo has measured against other 14" notebooks that comply with the Intel Ultrabook® specification. Lenovo ThinkPad X1 Carbon - 2.99lbs, Dell XPS 14Z - 4.12lbs, HP Envy 14 Spectre - 3.95lbs, Samsung Series 5 14" - 3.94lbs, Satellite U840 - 3.81lbs, Lenovo Thinkpad T430u - 4.05lbs, Fujitsu Lifebook U772 - 3.15lbs.

Ultrabook, Celeron, Celeron Inside, Core Inside, Intel, Intel Logo, Intel Atom, Intel Atom Inside, Intel Core, Intel Inside, Intel Inside Logo, Intel vPro, Itanium, Itanium Inside, Pentium, Pentium Inside, vPro Inside, Xeon, and Xeon Inside are trademarks of Intel Corporation in the U.S. and/or other countries.

Win - The new Thinkpad Tablet 2 with Windows 8 and built-in security.