Latest Windows 10 cumulative update slows systems, breaks connectivity, and can delete files

Dell XPS 13 9300
Dell XPS 13 9300 (Image credit: Daniel Rubino / Windows Central)

What you need to know

  • Some people have issues with the latest Windows 10 cumulative update, Windows 10 KB4549951.
  • Some can't install the update while it breaks Bluetooth and Wi-Fi connectivity for others.
  • A file deletion bug seems to affect some users as well.
  • The issue seems to affect a relatively small number of systems at this time.

Updated April 23, 2020: Reports have now emerged stating the update can cause file deletion bugs. We've updated this article with more details.

Another Windows 10 update is causing issues for people, though the issues seem to affect a relatively small number of systems (via Windows Latest). Windows 10 KB4549951 is failing to install onto some people's systems and breaking Bluetooth and Wi-Fi connectivity for others. Additionally, some people have seen their systems slow down significantly since the update or seen the "blue screen of death." Windows Latest also added several reports of a file deletition bug.

People went to Microsoft answers forums and Reddit to point out their issues with the update. Reddit user "fellow_netizen" experienced slowdowns following the update, stating:

Our environment: Pro Workstations Running 1909 on a Domain network.This KB4549951 update slowed networking to a crawl. Outlook 365 on hosted Exchange took several minutes to load/or freeze and Remote Desktop loaded to black screen to the target computer(s). This update also causes VM ware to freeze. Everything resumed to normal following uninstall and setting Updates to defer for 30 days.

One user on the Microsoft answer forums expressed frustration with the update's failure to install. Windows Latest also spotted a collection of complaints and received emails about Bluetooth and Wi-Fi breaking after the update and people seeing the "blue screen of death."

Some people reached out to Windows Latest following initial reporting of issues with the update to add that the update seems to also cause a file deletion bug. For affected people, their files were moved or deleted following the update.

Microsoft hasn't acknowledged any issues with the update at the time of publication. It's important to point out that Windows 10 is on over 1 billion systems, so there are often bugs and issues on a small subset of devices. While the issues may not be widespread, they can be frustrating for the everyday users and system admins that have to deal with them. If you want to remove the update, you should be able to do so following these steps:

  1. Select the start button or Windows Desktop Search and type update history and select View your Update history.
  2. On the Settings/View update history dialog window, Select Uninstall Updates.
  3. On the Installed Updates dialog window, find and select KB4549951and select the Uninstall button.
  4. Restart your device.
  5. Upon restart use, the "Reset this PC" feature (optional).
Sean Endicott
News Writer and apps editor

Sean Endicott brings nearly a decade of experience covering Microsoft and Windows news to Windows Central. He joined our team in 2017 as an app reviewer and now heads up our day-to-day news coverage. If you have a news tip or an app to review, hit him up at