NanoCoreTechnology

💻 Computer Not Booting (Updated 2025)

🛠️ Step-by-Step Boot Troubleshooting

Is your PC not turning on or failing to load Windows? Boot issues can arise from hardware, software, or firmware problems. This guide covers Windows, Mac, and Linux troubleshooting, hardware diagnostics, and prevention tips, updated for the latest Intel 15th Gen, AMD Ryzen 9000, and modern GPUs.

1️⃣ Preliminary Checks

  • 🔌 Power supply – Ensure cables and outlets work
  • 🔋 Laptop battery – Remove and reconnect
  • 🖥️ Peripheral devices – Disconnect USB drives, printers, external drives
  • 💡 Beep codes / LED indicators – Identify hardware faults
💡 Many “no boot” cases are solved by simple power and peripheral checks.

2️⃣ Windows PCs

2.1 ⚡ Safe Mode

  1. Power on → Press F8 or Shift + F8
  2. Select Safe Mode
  3. If boot succeeds → uninstall recent drivers or software causing issues

2.2 💻 Windows Recovery Environment (WinRE)

  1. Boot from Windows USB/DVD → Repair your computer
  2. Select Troubleshoot → Options:
    • Startup Repair – Automatic boot fix
    • System Restore – Roll back to previous state
    • Command Prompt – Run: 
      bootrec /fixmbr
bootrec /fixboot
bootrec /rebuildbcd

2.3 🔧 Hardware Checks

  • Reseat RAM modules
  • Check HDD/SSD connections
  • Disconnect non-essential components and retry boot

3️⃣ Mac Computers

3.1 🔋 Safe Boot

  1. Power on → Hold Shift until Apple logo appears
  2. Performs disk check & disables unnecessary extensions

3.2 💻 macOS Recovery

  1. Power on → Hold Command + R
  2. Use Disk Utility → Repair disk if needed
  3. Reinstall macOS if problem persists

3.3 🔧 Hardware Checks

  • Reset NVRAM/PRAM → Hold Option + Command + P + R
  • Reset SMC (System Management Controller)

4️⃣ Linux Systems

4.1 ⚡ Boot Loader Check

  1. If GRUB appears → Select recovery mode
  2. If GRUB doesn’t appear → Boot from live USB, check partitions and bootloader

4.2 🔧 Repair Boot Loader

  • Run in live session terminal: 
    sudo grub-install /dev/sda
sudo update-grub
  • Use fsck to verify disk integrity

4.3 💻 Minimal Hardware Boot

  • Reseat RAM, storage, and GPU
  • Disconnect non-essential peripherals

5️⃣ Hardware & Peripheral Troubleshooting

  • Disconnect external drives & USB devices
  • Reseat RAM, GPU, storage
  • Listen for BIOS beep codes for faulty components
  • Test PSU or laptop charger
💡 Hardware problems are the leading cause of total boot failure. Begin with power, RAM, and storage checks ✅.

📜 Summary Table: Boot Fixes

PlatformSolution / Tool
WindowsSafe Mode → WinRE → Startup Repair → bootrec commands → Hardware checks
MacSafe Boot → macOS Recovery → Disk Utility → NVRAM / SMC reset
LinuxGRUB recovery → Live USB → grub-install / update-grub → fsck → Minimal hardware boot
HardwareReseat RAM, storage, GPU → Disconnect peripherals → Check PSU / charger → Listen for beep codes
💡 Keep recovery media ready and perform regular backups. Most boot issues are software corruption or simple hardware faults that can be resolved with systematic checks ✅.
Posted on: November 16, 2025