For about two weeks, my Windows 11 Pro desktop started randomly freezing solid-no blue screen, no error message, just a total system lockup. It would happen anywhere from 10 minutes to an hour after startup. Sometimes the mouse pointer would freeze, sometimes it would still move but nothing else would respond. Only a hard reset would bring the PC back.

Here’s what I tried (in order):

Checked for Updates: Ran Windows Update, everything was up to date.
Driver Updates: Used Device Manager to check GPU, chipset, and storage drivers. Also installed newest NVIDIA drivers off their site.
Malware Scans: Ran both Windows Defender and Malwarebytes; nothing found.
Event Viewer Clues: Looked for errors during crash windows-only “Event 41 Kernel-Power,” which is as generic as it gets.
Memory Test: Ran Windows Memory Diagnostic and later Memtest86+ overnight. No problems reported.
Checked Storage: Ran chkdsk and CrystalDiskInfo on all drives-healthy according to them.
Clean Boot: Disabled all non-Microsoft services and startup items using MSConfig. Still froze up.
Replaced PSU and swapped RAM sticks: Had extras available, and even tried running with a single stick of RAM just in case.
Bios Update: Flashed to the latest version.

Absolutely none of this helped. At this point, I assumed I’d be re-installing Windows, but I was determined to figure out the cause. I finally noticed one weird thing: The crashes always happened when my USB Bluetooth adapter was plugged in and when I was using my Logitech Bluetooth mouse. No mouse, no crash. Wired mouse-no crash.

So I unplugged my cheapo ($8) USB Bluetooth adapter and switched to an old Logitech Unifying receiver instead. Haven’t had a single freeze in 5 days since.

My takeaways and tips if you’re banging your head against mysterious lockups:

Cheap USB adapters can cause havoc, even if Windows says drivers are fine. Try unplugging all USB accessories, even ones you think are “just working.”
If the system locks but doesn’t blue-screen, focus on hardware peripherals and don’t just go by what Windows Update or Device Manager says.
Event Viewer is often useless for hard freezes.
Cheap Bluetooth adapters are surprisingly common culprits for new Windows 11 installs-buy certified brands if you need one.

This one really had me stumped. Hope my story saves someone else’s sanity!