3xx post error code could pop up when the hard disk has not sufficient space.
computer BIOS might be incompatible or it might need to be updated.
Incorrectly configured, old, or corrupted device drivers.
device driver or a system service might be missing.
Corruption in Windows registry from a recent software change (install or uninstall).
- Start Your PC in safe mode to troubleshoot 3xx post error code
When booting, press F8. Your computer will enter into safe mode to run.
- Check if your PC drivers is outdated or not.
Click Start, type Device Manager in the searching box and see if there is outdated or corrupted driver issues.
Check for windows update with SmartPCFixer
Lionsea's technical team developed windows update function to help users largely save time and check for the latest windows update.
Launch the software and click System Tools, Windows update step by step.
From all the reasons above, it is clear that solving 3xx post error code is a little complicate for people. We suggest users use SmartPCFixer to cope with this problem.
1. Whatever steps you want to do for your computer, you had better run as an administrator.
2. Depending on the version of Windows you're using, the above steps may be slightly different, but the basic process is mostly the same.