Apparently an Israeli company claims to have built an ostensibly “unhackable version of Windows” using memory randomization and other techniques (emphasis added):

The Isreali security organization, Morphisec is presently working on making a Windows version that’s essentially not possible to hack, thus making it the appropriate operating system for military operations, which includes controlling of airlines and missiles.

Dudu Mimran, the co-founder of the company, in a statement to Business Insider, expressed this new OS version as the Windows that “Microsoft should be doing.” He further went to explain that though this new version OS was actually designed for government use, it can also be used by any company or undertaking who wants to ensure that hack is impossible.

The founder says that since the operating system randomizes all memory, it would not allow the hacker to target the memory of the computer and jeopardize the data stored on the drives, thus, blocking any zero-day attack.

Currently, the operating system is not available to the public. Mimra, who is also the CTO of Deutsche Telekom Innovation Laboratories in Israel and the Chief Security Officer of Cyber Security Research Center at Ben-Gurion University, says that such project has huge potential as the internal testing proved that 100 percent of the attacks could be blocked.

The company has until now raised $1.5 million from Israeli investors considering that developing such an operating system would require such finance to complete the work and make the platform available for use.

I may believe it when I see it but will likely still doubt the veracity of such a claim. It is hard to believe in 2015 that anything computing device could ever be considered unhackable, especially a closed-source operating system developed by Microsoft but fixed by a third-party.