Error code

Windows 0x0000004A

WINDOWS0x0000004A
System Error Code· A POSIX/system errno returned when a system call fails.

What it means

IRQL_GT_ZERO_AT_SYSTEM_SERVICE — a thread returned to user mode from a system call while its IRQL was still above PASSIVE_LEVEL..

How to fix it

  1. Enable Driver Verifier to identify the offending driver.
  2. update or roll back recently installed drivers.
  3. boot into Safe Mode to isolate the cause.
  4. run sfc /scannow and DISM RestoreHealth.
  5. remove recent hardware or driver changes.

Not affiliated with Windows. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.