2018 in PC-land has been dominated by a lot of nervous sideways glances about whether or not the security flaw affecting pretty much every processor going is a clear and present danger or just Millennium Bug 2.0. Katherine has written us a good explainer for the CPU exploits known as Meltdown and Spectre, and the industry at large has been fast-tracking patches.
Sadly these bring with them a theoretical performance hit, although this seems negligible if not non-existent when it comes to games specifically. Rather more problematic is that Microsoft's official fix for Windows has itself been causing chaos - to the point that it's been hastily withdrawn for the clutch of AMD processors it's been causing BSODs and bootloops on. Oops.
For their part, Microsoft is arguing that the fault lies with inadequate documentation provided to them by AMD when preparing the update - i.e. they ran into problems they didn't know existed. The result of which has been preventing some AMD users' PCs from booting up.
Say MS alongside a list of which Windows Updates for Windows 7-10 have been halted until all this has been sorted out:
"Microsoft has reports of customers with some AMD devices getting into an unbootable state after installing recent Windows operating system security updates. After investigating, Microsoft has determined that some AMD chipsets do not conform to the documentation previously provided to Microsoft to develop the Windows operating system mitigations to protect against the chipset vulnerabilities known as Spectre and Meltdown. 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."
AMD, meanwhile, are little more brief, their statement sent to us (and every other site in town) reading simply that "AMD is aware of an issue with some older generation processors following installation of a Microsoft security update that was published over the weekend. AMD and Microsoft have been working on an update to resolve the issue and expect it to begin rolling out again for these impacted shortly."
There isn't a totally clear picture of exactly which CPUs are affected as yet, but, as mentioned above, grumbles seem focused around older models such as the Athlon 64 X2 range, which ceased production in 2009.
As such, it's quite unlikely this applies to you, but if you have an older second machine or have needy relatives with more antiquated devices, it's well worth being aware of. As it stands, you should be safe as the problem patches have been withdrawn and fixed replacements will arrive soon, but this whole Spectre/Meltdown affair is such a mess that exercising caution and double-checking before installing any purported fixes only makes sense .
If you downloaded the problem patch before you heard about these latest woes, there aren't any specific fixes to get your PC running again, but Microsoft's general advice about how to resolve bluescreens (safe mode, rollbacks, etc) here might see you through.