Common Computer, Browser, Windows & System Error Codes

1. HTTP / Browser Error Codes

1xx – Informational

• 100 Continue
• 101 Switching Protocols

2xx – Success

• 200 OK
• 201 Created
• 204 No Content

3xx – Redirection

• 301 Moved Permanently
• 302 Found
• 304 Not Modified
• 307 Temporary Redirect

4xx – Client Errors

• 400 Bad Request
• 401 Unauthorized
• 403 Forbidden
• 404 Not Found
• 405 Method Not Allowed
• 408 Request Timeout
• 409 Conflict
• 429 Too Many Requests

5xx – Server Errors

• 500 Internal Server Error
• 501 Not Implemented
• 502 Bad Gateway
• 503 Service Unavailable
• 504 Gateway Timeout

2. Common Browser Errors

Google Chrome

• ERR_CONNECTION_TIMED_OUT
• ERR_CONNECTION_REFUSED
• ERR_NETWORK_CHANGED
• ERR_NAME_NOT_RESOLVED
• ERR_SSL_PROTOCOL_ERROR
• ERR_CERT_COMMON_NAME_INVALID
• ERR_INTERNET_DISCONNECTED

Mozilla Firefox

• PR_CONNECT_RESET_ERROR
• SSL_ERROR_BAD_CERT_DOMAIN
• SEC_ERROR_UNKNOWN_ISSUER
• Server Not Found

Microsoft Edge

• INET_E_RESOURCE_NOT_FOUND
• DNS_PROBE_FINISHED_NXDOMAIN
• Hmmm… Can't Reach This Page

3. Windows Blue Screen (BSOD) Errors

Hardware Related

• WHEA_UNCORRECTABLE_ERROR
• MACHINE_CHECK_EXCEPTION
• CLOCK_WATCHDOG_TIMEOUT
• HARDWARE_INTERRUPT_STORM

Driver Related

• DRIVER_IRQL_NOT_LESS_OR_EQUAL
• SYSTEM_THREAD_EXCEPTION_NOT_HANDLED
• DRIVER_POWER_STATE_FAILURE
• KMODE_EXCEPTION_NOT_HANDLED

Memory Related

• MEMORY_MANAGEMENT
• PAGE_FAULT_IN_NONPAGED_AREA
• PFN_LIST_CORRUPT
• BAD_POOL_HEADER

Disk Related

• CRITICAL_PROCESS_DIED
• NTFS_FILE_SYSTEM
• UNMOUNTABLE_BOOT_VOLUME
• INACCESSIBLE_BOOT_DEVICE

4. Windows System Error Codes

Installation Errors

• 0x80070005 → Access Denied
• 0x80070002 → File Not Found
• 0x80070057 → Invalid Parameter
• 0x80070422 → Service Disabled

Windows Update Errors

• 0x80073712
• 0x800f081f
• 0x8024402C
• 0x80240034

Activation Errors

• 0xC004F074
• 0xC004C003
• 0x803F7001

5. Network Error Codes

DNS Errors

• DNS_PROBE_FINISHED_NXDOMAIN
• DNS_SERVER_NOT_RESPONDING
• DNS_PROBE_STARTED

Connection Errors

• Connection Timed Out
• Connection Refused
• Host Unreachable
• Network Unreachable

IP Configuration Errors

• Limited Connectivity
• IP Address Conflict
• DHCP Server Unavailable

6. Windows Run-Time Errors

• Runtime Error 5
• Runtime Error 9
• Runtime Error 13
• Runtime Error 53
• Runtime Error 70
• Runtime Error 91

7. Microsoft Office Errors

Excel

• #DIV/0!
• #NAME?
• #VALUE!
• #REF!
• #N/A
• #NUM!
• #NULL!

Word

• Word Cannot Open File
• File Permission Error
• Normal.dotm Corruption

Outlook

• 0x800CCC0E
• 0x8004210A
• 0x8004010F

8. Hard Disk & Storage Errors

• SMART Failure Predicted
• Disk Read Error Occurred
• No Bootable Device Found
• Operating System Not Found
• CRC Error
• Bad Sector Error

9. BIOS/Boot Errors

• CMOS Checksum Error
• CMOS Battery Failure
• Boot Device Not Found
• PXE-E61 Media Test Failure
• Invalid Partition Table
• Missing Operating System

10. Command Prompt Exit Codes

• 0 → Success
• 1 → General Error
• 2 → Misuse of Shell Command
• 126 → Cannot Execute
• 127 → Command Not Found
• 128 → Invalid Exit Argument
• 130 → Script Terminated by Ctrl+C

11. Common Programming Error Types

Syntax Errors

• Missing Semicolon
• Invalid Syntax
• Unexpected Token

Runtime Errors

• Divide By Zero
• Null Pointer Exception
• Segmentation Fault
• Stack Overflow

Logical Errors

• Infinite Loop
• Incorrect Formula
• Wrong Condition

12. Database Error Codes

MySQL

• Error 1045 → Access Denied
• Error 1064 → SQL Syntax Error
• Error 2002 → Connection Failed

Oracle

• ORA-00001
• ORA-00904
• ORA-12154

SQL Server

• Error 18456
• Error 4060
• Error 547

13. Common Windows Commands for Troubleshooting

• sfc /scannow
• DISM /Online /Cleanup-Image /RestoreHealth
• chkdsk /f /r
• ipconfig /flushdns
• ipconfig /release
• ipconfig /renew
• netsh winsock reset

Most Important Exam-Oriented Errors

• 404 → Page Not Found
• 403 → Forbidden
• 500 → Internal Server Error
• BSOD → Blue Screen of Death
• DNS_PROBE_FINISHED_NXDOMAIN → DNS Resolution Failure
• 0x80070005 → Access Denied
• 0x80070002 → File Not Found
• #DIV/0! → Division by Zero
• Error 1045 (MySQL) → Access Denied
• Exit Code 127 → Command Not Found