Windows 10 KB4559309 Update Could Be Killing System Performance, But Here's A Fix

Windows 10 Slow
Does your PC seem abnormally slow or has it been acting a bit wonky as of late? There are a plethora of reasons for these kinds of symptoms—welcome to the world of Windows, and PCs in general—but one possible culprit is a recent Microsoft Edge update. It is supposed to make Edge better at what it does, though some users have reported various issues after applying the update.

There are actually three recent updates related to the Edge browser, those being KB4559309, KB4541301, and KB4541302. You would have only received one of them, depending on which version of Windows 10 you are running. And only one of them appears to be problematic, at least for some users. That is the KB4559309 update.

"Last night I updated my Windows 10 Pro using KB:4559309. Since then my computer performance has absolutely tanked. My startup time is probably triple, loading any window has a few seconds delay... This update has essentially rendered my brand new computer useless," a user wrote on Microsoft's support forums.

Several of the responses in the ongoing thread say they too have experienced performance issues after applying the update. In some cases, the issues extend beyond slowdowns. One user says their external hard drive stopped working after the update.

What makes this even more frustrating for affected users is that the option to uninstall the KB4559309 update does not work. So, what can you do if you are affected by this? The best option is to perform a system restore to revert back to a previous version of Windows.

You can do this by navigating to Control Panel > All Control Panel Items > Recovery, then click on Open System Restore and follow the prompts. It's not ideal, but it's better than having a PC that does not run optimally.

As spotted by Windows Latest, Microsoft also offers an optional "Blocker Toolkit" to disable the automatic delivery and installation of Edge.