IT Support & Troubleshooting Knowledge Base
Structured articles for problems technicians, network engineers, and security teams hit at work — each with symptoms, causes, diagnostic commands, a step-by-step fix, and when to escalate.
Computer Cannot Connect to the Internet
A Windows computer has no internet access, either on Wi-Fi or Ethernet, despite appearing to be connected to the local network.
Windows Login Problems
A user cannot log into a Windows computer, either locally or with a domain/Microsoft account.
Blue Screen (BSOD) Troubleshooting
A Windows machine crashes to a blue screen with a stop code, either occasionally or repeatedly.
APIPA / 169.254.x.x Addresses
A device has self-assigned an IP address in the 169.254.0.0/16 range instead of getting one from DHCP.
DNS Resolution Failures
A device can reach the internet by IP address but cannot resolve domain names.
High Latency and Packet Loss
A connection works but is slow or unreliable, with high ping times or dropped packets.
Outlook Not Connecting / Sending-Receiving Mail
Outlook desktop or mobile shows a connection error, or mail is not sending or arriving.
MFA Issues and Account Lockouts (Microsoft 365)
A user cannot complete multi-factor authentication, or their Microsoft 365 account is locked.
Account Lockouts in Active Directory
A domain user account is locked out and the user cannot log in anywhere.
Group Policy Not Applying
A Group Policy Object is configured but its settings are not taking effect on target machines or users.
Phishing Email Investigation
A user reports a suspicious email that may be a phishing attempt.
Suspicious PowerShell Activity / Endpoint Alert
Endpoint security software flags unusual PowerShell activity on a device.