Windows & BSOD · critical

How to fix IRQL_GT_ZERO_AT_SYSTEM_SERVICE0x0000004A

Windows & BSOD troubleshooting guide

What this error means

A critical Windows error indicating that a system service was accessed with an IRQL that was too high. This usually traces back to incompatible software (antivirus, firewall) and bad device driver.

Updated

Before you begin

Save open work and back up important files. Use instructions for your exact device and software version. If Windows cannot start, see the startup guide.

Work through these checks

0 of 3 complete
01Start your PC in safe mode and remove recent software
  1. Start your PC in safe mode and remove recent software
What to expect

Check whether the original symptom still occurs.

If it does not help

Continue only if this check applies to your device. Consult its manufacturer if you are unsure.

Browse related errors
02Check the
  1. Check the
What to expect

Check whether the original symptom still occurs.

If it does not help

Continue only if this check applies to your device. Consult its manufacturer if you are unsure.

Browse related errors
03drivers Restore the system to the previous point
  1. drivers Restore the system to the previous point
What to expect

Check whether the original symptom still occurs.

If it does not help

Continue only if this check applies to your device. Consult its manufacturer if you are unsure.

Browse related errors

Possible causes

  • Incompatible software (antivirus, firewall)
  • Bad device driver
  • Hardware error