http://www.techradar.com/news/dont-download-intels-latest-spectre-and-meltdown-patch-intel-warns

If you own a PC or Mac using an Intel processor and have been patiently waiting for Spectre and Meltdown patches appear on Windows Update or Mac App Store updates, you shouldn't download it.

That’s the latest directive from Intel, who cited spontaneous reboot and system instability problems – first reported January 11 – following its latest firmware patch aimed to defend against the Spectre and Meltdown exploit vulnerabilities. The company issued a blog post today warning both its partners and end users.