Windows Error Codes
Searchable reference for Windows error codes — system errors, BSOD stop codes, NTSTATUS, WMI, RPC, MSI installer, AD/Kerberos, BitLocker, DNS, VPN, Hyper-V, COM/DCOM and more. Each entry includes the hex/decimal value, severity, root causes, and a step-by-step troubleshooting workflow.
How to read a Windows error code
Windows surfaces error codes through Win32, NTSTATUS, HRESULT, and many subsystem-specific spaces. Each code has a hex form (e.g. 0x80070005), a signed decimal form (-2147024891), and a symbolic name (ERROR_ACCESS_DENIED). This page lets you look up any of those forms, see what triggers the code, and follow a vetted troubleshooting workflow tuned for the originating subsystem (Windows Update, BSOD, AD/Kerberos, BitLocker, etc.).
4 codes
0x80072745ErrorWSAECONNABORTED
An established connection was aborted by the software in your host machine.
0x80072746ErrorWSAECONNRESET
An existing connection was forcibly closed by the remote host. VPN server dropped the connection.
0x800B0109ErrorCERT_E_UNTRUSTEDROOT
Certificate chain processed but terminated in a root certificate which is not trusted. VPN certificate issue.