Windows 10 users have been and continue to be affected by an issue where their CPU usage quickly soars really high (sometimes up to 100%) because of extremely high hard disk bandwidth usage by a process named gfxui.exe, ultimately making their computer unbearably sluggish. The gfxui.exe process is a process associated with Intel GPUs, which is why this problem only affects users that have Intel GPUs in their computers. However, this problem is especially rampant among computers and laptops that have two graphics cards – an Intel HD Graphics card for display and an NVIDIA/AMD graphics card for dedicated graphics (playing graphically demanding games, for example).
In most cases, it is either a clash between two graphics cards or an issue with the Intel HD Graphics drivers that causes the gfxui.exe process to use a lot of hard disk bandwidth and lead to high CPU usage. Thankfully, though, this issue can be fixed by simply uninstalling and then reinstalling the Intel HD Graphics drivers.