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.

“We recommend that OEMs, cloud service providers, system manufacturers, software vendors, and end users stop deployment of current versions on specific platforms,” Intel EVP Neil Shenoy writes, “as they may introduce higher than expected reboots and other unpredictable system behavior.”

Intel is just now getting to the bottom of the problem, having identified the root cause of these issues in Broadwell and Haswell-generation chips. The firm claims to have already issued early versions of fixes for these issues to its partners, but not yet a final release.

Microsoft patches Windows to cool off Intel's Meltdown – wait, antivirus? Slow your roll. More stuff broken amid Microsoft's efforts to fix Meltdown/Spectre vulns. This is going to take a while. Earlier this month I shared news on Microsoft’s continuing efforts to help protect our customers against the Spectre and Meltdown hardware-based vulnerabilities. You can always choose to install the Fall Creators Update from the Software Download Site. Update on Spectre and Meltdown security updates for Windows devices Read more.

For the latest on how to protect yourself from Spectre and Meltdown, read our comprehensive guide linked above.

However, Intel has yet to directly address similar issues affecting both older and more recent processors than the Broadwell and Haswell families, namely Ivy Bridge, Skylake, Kaby Lake, and Coffee Lake generations. However, it has named processors from those families as suffering from the problem in official documentation.

In short, while computing device vendors and other Intel partners work with Intel to fix these issues at the top level and hopefully avoid these faulty patches, the firm also asking end users to stay away from the latest processor updates. However, the firm stresses users should keep their devices up-to-date and secure with with all other software releases.

(Don't worry, AMD is suffering a similar fate, with Microsoft recently having to halt a patch from the firm for similar reasons.)

If your machine automatically updates through Windows 10 Update or the Mac App Store and you’re experiencing these problems, it’s unknown when a fix will be available for you.

• These are the best processors to date, bar none

Microsoft said on Tuesday it had suspended patches to guard against Meltdown and Spectre security threats for computers running AMD chipsets after complaints by AMD customers that the software updates froze their machines.

Microsoft said in a support blog that it was working with AMD to resolve the issues and would resume Windows operating system software updates to affected AMD devices via its Windows Update process as soon as possible.

AMD shares dipped 1.3 percent in pre-market U.S. trading.

Microsoft said in a support blog that it was working with AMD to resolve the issues and would resume Windows operating system software updates to affected AMD devices via its Windows Update process as soon as possible. Pictured, silicon up close (stock image)

Last week the stock rose nearly 20 percent as investors speculated AMD could wrest market share from Intel, whose chips are exposed to risks from possible Meltdown and Spectre attacks.

'To prevent AMD customers from getting into an unbootable state, Microsoft will temporarily pause sending the following Windows operating system updates to devices with impacted AMD processors at this time,' Microsoft said in its statement.

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Meltdown And Spectre Patch

Microsoft said it had received complaints from AMD customers that their machines stopped loading the Start menu or taskbar after installing Windows operating system security updates.

Upon investigation, Microsoft said some AMD chipsets did not conform to technical documentation the chipmaker had provided, preventing Microsoft from successfully patching affected machines.

WHAT ARE THE MELTDOWN AND SPECTRE DESIGN FLAWS?

Researchers from Google, academia and cybersecurity firms discovered two flaws in computer chips that affect nearly all modern computers:

Meltdown

This is a flaw that affects laptops, desktop computers and internet servers with Intel chips.

It lets hackers bypass the hardware barrier between applications run by users and the computer's kernel memory.

Free Microsoft Patch Download

This has the potential to let hackers access the content of this portion of a computer's memory.

This would enable them to steal data, such as passwords saved in web browsers.

Free Microsoft Patch

Spectre

This bug affects chips from Intel, AMD and ARM and lets hackers potentially trick otherwise error-free applications into giving up secret information.

'Spectre' affects chips in smartphones and tablets, as well as computer chips from Intel and Advanced Micro Devices Inc.

Hackers can trick apps into leaking sensitive information.

Spectre is a broader bug that applies to nearly all computing devices.

It is harder for hackers to take advantage of but less easily patched and will be a bigger problem in the long term, experts say.

In its blog post, the software giant said the patches had caused computer screens to freeze up, or have so-called 'blue screen errors' on Windows 10, Windows 8.1 and Windows 7.

Meltdown and Spectre are two memory corruption flaws which could allow hackers bypass operating systems and other security software to steal passwords or encryption keys, on most types of computers, phones and cloud-based servers.

AMD said last week that differences in its chip designs from rival Intel Corp meant its products were at 'zero risk' from Meltdown flaw but that one variant of the Spectre bug could be resolved by software updates from vendors such as Microsoft.

AMD was not immediately available for further comment. (Reporting by Eric Auchard; Editing by Georgina Prodhan and Edmund Blair)