Hi

The internet reports ...

That warning means the PCIe link negotiated only x1 lanes even though the device reports x4 capability, so the fix is usually to check slot/cable compatibility, update BIOS/firmware, and then retrain or reseat the device if needed.

Please can you confirm the Make Model and OS, along with any configuration details like touch screen, backlit keyboard, SFF or tower etc etc.

Just give what details you can,that  are non-personal.

@anne_droid​ it's a dell latitude 3420 p144g201 with Microsoft windows 11 pro, no touchscreen and no backlit keyboard 

did you have this problem before installing this month windows updates ? 

@mazzinia_​ No, i didn't have the PCIe error

@Akc2217​ check this

https://www.dell.com/community/en/conversations/supportassist-for-pcs/bsod-random-reboots-may-2026-dell-updates-dell-support-assist-probable-cause/6a017bde657052398888e805

you can check what you have installed / remove what you don't need.

2nd option is to rollback the monthly windows update, then start digging the error logs to find out with calm which software is misbehaving.

@Akc2217​ check this https://www.dell.com/community/en/conversations/supportassist-for-pcs/bsod-random-reboots-may-2026-dell-updates-dell-support-assist-probable-cause/6a017bde657052398888e805 cool games

you can check what you have installed / remove what you don't need.2nd option is to rollback the monthly windows update, then start digging the error logs to find out with calm which software is misbehaving.

I followed your suggestion and checked/uninstalled recent installs and even rolled back the latest Windows update, but the issue is still happening. The BSODs (UNEXPECTED_STORE_EXCEPTION, KMODE_EXCEPTION_NOT_HANDLED, CRITICAL_PROCESS_DIED) keep coming back, and the Dell diagnostics still show the PCIe-Training warning with the link degraded (x4 → x1).

@johnfleck​ ach. it could be the nvme drive having issues to its internal controller