Common Issues
Server Issues
Utilities
Quick Fixes
Command Reference

DNS Resolution Issues

Unable to resolve domain names to IP addresses. Websites not loading but IP access works.

Networking
  1. Open Command Prompt as Administrator
  2. Run: ipconfig /flushdns
  3. Run: ipconfig /registerdns
  4. Run: netsh winsock reset
  5. Restart your computer
  6. Check DNS server settings (should be automatic or use 8.8.8.8/1.1.1.1 for testing)
  7. Check hosts file for incorrect entries: %SystemRoot%\System32\drivers\etc\hosts

High CPU Usage

System slowing down due to processes consuming excessive CPU resources.

Performance
  1. Open Task Manager (Ctrl+Shift+Esc)
  2. Sort processes by CPU usage
  3. Identify the problematic process
  4. Research the process online if unfamiliar
  5. End task or investigate further
  6. Check for malware if unknown process
  7. Update drivers and Windows
  8. Check for power plan settings
  9. Run full antivirus scan
  10. Check for Bitcoin mining malware
  11. Disable unnecessary startup programs

Disk Space Critical

System drive running out of space, affecting performance and functionality.

Storage
  1. Run Disk Cleanup utility
  2. Clean system files through the utility
  3. Remove temporary files (%temp%)
  4. Uninstall unused applications
  5. Move large files to another drive
  6. Consider resizing partitions
  7. Disable hibernation: powercfg -h off
  8. Reduce system restore points
  9. Clear browser caches
  10. Use TreeSize to identify large folders
  11. Move virtual memory to another drive

Windows Update Failures

Windows Update failing to download or install updates with error codes.

Update
  1. Run Windows Update Troubleshooter
  2. Stop Windows Update service
  3. Delete SoftwareDistribution folder contents
  4. Restart Windows Update service
  5. Run: sfc /scannow
  6. Run: DISM /Online /Cleanup-Image /RestoreHealth
  7. Check for sufficient disk space
  8. Manually download and install updates
  9. Reset Windows Update components: net stop wuauserv, net stop cryptSvc, net stop bits, net stop msiserver
  10. Rename SoftwareDistribution and Catroot2 folders
  11. Restart services: net start wuauserv, net start cryptSvc, net start bits, net start msiserver

Blue Screen of Death

System crashing with blue screen and error code, then restarting.

Hardware
  1. Note the error code displayed
  2. Check if recent hardware/software changes
  3. Boot into Safe Mode
  4. Update device drivers
  5. Run memory diagnostics
  6. Check disk for errors
  7. Use System Restore if needed
  8. Check hardware components
  9. Check minidump files in C:\Windows\Minidump
  10. Use BlueScreenView to analyze crash dumps
  11. Check Event Viewer for related errors

Slow Boot Times

Windows takes an excessively long time to start up and become usable.

Performance
  1. Open Task Manager → Startup tab
  2. Disable unnecessary startup programs
  3. Check for outdated drivers
  4. Run disk cleanup and defragmentation
  5. Check for malware
  6. Adjust BIOS/UEFI settings
  7. Consider hardware upgrade (SSD, more RAM)
  8. Check for slow network drives in startup
  9. Use Windows Performance Toolkit to analyze boot performance
  10. Disable unnecessary services
  11. Check for Group Policy processing delays

Wi-Fi Connectivity Issues

Unable to connect to Wi-Fi networks or intermittent connectivity.

Networking
  1. Restart your router and modem
  2. Forget the network and reconnect
  3. Update wireless adapter drivers
  4. Reset TCP/IP stack: netsh int ip reset
  5. Check power management settings for wireless adapter
  6. Change Wi-Fi channel on router
  7. Move closer to the router
  8. Check for interference from other devices
  9. Run network diagnostics
  10. Disable and re-enable wireless adapter

Application Crashes

Specific applications crashing or not opening properly.

Application
  1. Check Event Viewer for application errors
  2. Update the application
  3. Reinstall the application
  4. Check for compatibility issues
  5. Run application as administrator
  6. Check if .NET Framework needs updating
  7. Check if Visual C++ Redistributables are installed
  8. Check for conflicting software
  9. Check application logs
  10. Test with clean boot

Boot Loop / Unable to Start

Computer stuck in restart cycle or unable to boot into Windows.

Boot
  1. Boot into Safe Mode
  2. Use System Restore
  3. Run Startup Repair
  4. Use Command Prompt from recovery environment
  5. Check disk: chkdsk C: /f /r
  6. Rebuild BCD: bootrec /rebuildbcd
  7. Check for recently installed software/hardware
  8. Test RAM with Windows Memory Diagnostic
  9. Use System File Checker: sfc /scannow
  10. Consider resetting Windows (keep files)

Virus/Malware Infection

Suspected malware infection causing various system issues.

Security
  1. Boot into Safe Mode with Networking
  2. Run full scan with Windows Defender
  3. Run Malwarebytes scan
  4. Check Task Manager for suspicious processes
  5. Check startup programs
  6. Check browser extensions
  7. Reset browsers to default settings
  8. Use AdwCleaner for adware
  9. Check scheduled tasks
  10. Consider system restore if recent infection

Active Directory Replication

Domain controllers failing to replicate Active Directory information.

Server Services
  1. Check network connectivity between DCs
  2. Verify DNS resolution for DCs
  3. Run: repadmin /replsummary
  4. Check event logs for errors
  5. Force replication with: repadmin /syncall
  6. Check for time synchronization issues
  7. Verify SYSVOL and Netlogon shares
  8. Check for sufficient disk space on DCs
  9. Check Active Directory Database integrity
  10. Verify replication topology

DHCP Server Issues

DHCP server not assigning IP addresses to clients.

Server Services
  1. Verify DHCP service is running
  2. Check available IP addresses in scope
  3. Verify authorization in Active Directory
  4. Check for conflicts with static IPs
  5. Review DHCP server logs
  6. Restart DHCP service
  7. Reconcile DHCP database
  8. Check DHCP server bindings
  9. Verify DHCP relay agents configuration
  10. Check for network connectivity issues

DNS Server Issues

DNS server not resolving queries or responding slowly.

Server Services
  1. Check DNS service is running
  2. Verify forwarders are configured correctly
  3. Check DNS server cache
  4. Verify zone transfers are working
  5. Check for event log errors
  6. Test recursion
  7. Clear DNS server cache: dnscmd /clearcache
  8. Check DNS server performance counters
  9. Verify network connectivity
  10. Check for sufficient resources (CPU, memory)

Group Policy Not Applying

Group Policy settings not applying to clients or applying incorrectly.

Server Services
  1. Run gpupdate /force on client
  2. Check gpresult /r to see applied policies
  3. Verify network connectivity to domain controller
  4. Check time synchronization
  5. Verify DNS resolution
  6. Check Group Policy replication
  7. Review event logs on client and server
  8. Check permissions on Group Policy Objects
  9. Verify GPO links in correct OUs
  10. Check for conflicting GPOs

Hyper-V VM Issues

Virtual machines not starting or performing poorly.

Server Services
  1. Check Hyper-V service is running
  2. Verify host has sufficient resources
  3. Check virtual switch configuration
  4. Verify VM configuration files
  5. Check integration services are installed and updated
  6. Review event logs
  7. Check storage space for VM files
  8. Verify processor compatibility settings
  9. Check virtual networking configuration
  10. Test with different VM configurations

System Utilities

System File Checker

Scans and repairs system files

DISM Tool

Repairs Windows image

Disk Cleanup

Cleans temporary files

Performance Monitor

Monitors system performance

System Configuration

Manages startup and services

Event Viewer

Views system event logs

Task Scheduler

Manages automated tasks

Registry Editor

Modifies system registry

Services

Manages system services

System Information

Displays system details

Network Connections

Manages network adapters

Windows Defender

Virus and threat protection

Common Quick Fixes

Network Reset

  1. Open Settings → Network & Internet
  2. Click on "Network reset"
  3. Click "Reset now"
  4. Restart your computer

Display Driver Reinstall

  1. Press Win + X → Device Manager
  2. Expand Display adapters
  3. Right-click graphics card → Uninstall device
  4. Check "Delete the driver software"
  5. Restart and let Windows reinstall driver

Clean Boot

  1. Type "msconfig" in Run dialog
  2. Go to Services tab
  3. Check "Hide all Microsoft services"
  4. Click "Disable all"
  5. Go to Startup tab → Open Task Manager
  6. Disable all startup items
  7. Restart your computer

Rebuild Search Index

  1. Open Indexing Options
  2. Click Advanced
  3. Click Rebuild
  4. Confirm and wait for process to complete

Reset Windows Update

  1. Stop Windows Update service
  2. Rename SoftwareDistribution folder
  3. Rename Catroot2 folder
  4. Restart Windows Update service
  5. Try updating again

Fix Keyboard/Mouse Issues

  1. Check physical connections
  2. Try different USB ports
  3. Restart computer
  4. Update drivers in Device Manager
  5. Check Power Management settings

Command Reference

Networking Commands

  • ipconfig /all - Display full network configuration
  • ping [host] - Test network connectivity
  • tracert [host] - Trace network path
  • netsh winsock reset - Reset Winsock catalog
  • netsh int ip reset - Reset TCP/IP stack
  • nslookup [domain] - DNS lookup tool

Disk & File Commands

  • chkdsk C: /f - Check and fix disk errors
  • sfc /scannow - System File Checker
  • diskpart - Disk partitioning tool
  • robocopy [source] [dest] - Advanced file copy
  • dir /s - List directory contents recursively
  • tree - Display directory structure

System Info Commands

  • systeminfo - Display system configuration
  • tasklist - Display running processes
  • whoami - Display current user
  • hostname - Display computer name
  • ver - Display Windows version
  • driverquery - Display installed drivers

Server Management

  • gpupdate /force - Update Group Policy
  • gpresult /r - Display applied policies
  • repadmin /replsummary - AD replication summary
  • dcdiag - Domain controller diagnostics
  • netdom - Domain management工具
  • dsquery - Directory service query

Troubleshooting Commands

  • DISM /Online /Cleanup-Image /RestoreHealth - Repair Windows image
  • sfc /scannow - System File Checker
  • chkdsk C: /f /r - Check disk and recover data
  • verifier - Driver Verifier Manager
  • msdt - Microsoft Support Diagnostic Tool
  • powercfg /energy - Energy efficiency diagnostics

PowerShell Basics

  • Get-Service - Display services
  • Get-Process - Display processes
  • Get-EventLog - Read event logs
  • Test-NetConnection - Network connectivity test
  • Get-WindowsUpdateLog - Get update logs
  • Get-HotFix - Display installed updates

Admin Terminal

PowerShell 7.2

# Welcome to Windows Troubleshooting Assistant

# Type commands or click buttons to execute them

PS C:\> _