USB-C bug in Windows 10 is slowing down systems

Windows 10 start menu
(Image credit: Microsoft)

Users who are currently running the Windows 10 October 2018 update may be experiencing a slowing of their systems due to a known bug affecting USB-C drives.

The bug is hardly as devastating as some others and there are no vulnerabilities to be exploited, but affected users are reporting delays of up to one minute when shutting down their computers, something that could get very irritating to people working on the move.

The bug can be triggered if users connect or disconnect a USB-C device from their computer as they either put the computer to sleep or initialise a restart. It's not uncommon for users, especially office workers using laptops, to pull all peripherals out of a computer before shutting the lid and quickly zipping off home after a long day.

Microsoft acknowledged the bug's existence in a blog post, saying that it only affects Windows 10 1809 (October update) and has now been fixed in the most recent 1903 May update. Microsoft still hasn't listed the bug in it's 'known issues' page for the Windows 10 1809 release, though.

"A bug in the USB Type-C Connector System Software Interface (UCSI) software implementation in Windows 10, version 1809 can cause a 60 second delay in the system sleep or shutdown process if the power-down happens while the UCSI software is busy handling a new connect or disconnect event on a USB Type-C port," said Microsoft's Philip Froese.

He added that other than the minor delay in sleep or shutdown times, the bug won't affect the normal functionality of USB-C on the computer.

Delayed sleep or shutdown processes also shouldn't alter the way devices operate when connected to the computer after powering back on.

The bug shouldn't be too impactful on any of the affected users, but will come as an annoyance to those who demand peak performance out of their machine.

While Microsoft recommends updating to the latest version of Windows 10, as does the wider industry from a security standpoint, the latest release hasn't been without its issues.

Some users were left unable to update to the latest May 2019 update because they had external USB storage devices or SD cards connected to their machines.

The company confirmed just a few weeks before the release date for 1903 that the update suffered from an "inappropriate drive reassignment" error that would also affect internal hard drives too, in some cases.

Microsoft also announced an overhaul in the way it rolls out updates in the future, in the hope that it will avoid the rollout disasters experienced in both the April and October 2018 updates.

1903 piloted the new method of update release which involved notifying a user when an update was ready to be made instead of simply automatically performing it. It also separated the major updates from regular security updates and patches which for the first time could be initialised separately and now deferred by up to 35 days.

Connor Jones

Connor Jones has been at the forefront of global cyber security news coverage for the past few years, breaking developments on major stories such as LockBit’s ransomware attack on Royal Mail International, and many others. He has also made sporadic appearances on the ITPro Podcast discussing topics from home desk setups all the way to hacking systems using prosthetic limbs. He has a master’s degree in Magazine Journalism from the University of Sheffield, and has previously written for the likes of Red Bull Esports and UNILAD tech during his career that started in 2015.