A botched update can block startup; use power checks, Safe Mode, and recovery tools to roll back the update and boot again.
Computer Not Turning On After Update: Fast Checklist
Start with the simple stuff, then move to recovery. These quick checks save time and protect your files.
| Symptom | What It Likely Means | Try First |
|---|---|---|
| No lights, no fans | No power or a tripped power brick | Check outlet, cable, power strip; reseat cord; try another socket |
| Lights/fans, black screen | Display path issue or sleep hang | External monitor test; brightness keys; force shutdown, then cold boot |
| Logo loop or “Preparing Automatic Repair” | Boot files damaged by the update | Interrupt boot 3× to open Recovery; run Startup Repair |
| Blue screen then reboot | Driver or patch conflict | Safe Mode; uninstall the latest update; update or roll back drivers |
| Mac shows a question mark folder | Startup disk not found | Power cycle; Safe Mode; select startup disk; run First Aid in Recovery |
| Endless “Undoing changes” | Failed update rollback | Use Recovery to remove the last update or restore a point/image |
Why Updates Sometimes Break Startup
Updates touch low-level pieces: bootloaders, drivers, and system files. If power drops mid-install, storage is full, or a driver misbehaves, the boot chain can fail. The fix is to restore a known-good state without wiping personal data.
Step 1: Rule Out Power And Peripherals
Do A Proper Power Reset
Shut the machine down fully. On a laptop, disconnect the charger. Hold the power button for 15 seconds to drain residual power. Reconnect and try again. Desktops: flip the PSU switch off for 30 seconds, then on. Many “dead after update” cases are actually a sleep or hibernation hang.
Unplug Extras
Remove docks, adapters, external drives, printers, and SD cards. Reboot with only keyboard, mouse, and display. Faulty USB firmware or a mis-tagged boot device can stall startup.
Step 2: Try Safe Mode
Safe Mode loads a minimal set of drivers. If the computer starts here, the update likely clashed with a driver or service.
Windows: Open Safe Mode
Power on and interrupt boot three times to open Windows Recovery. Select Troubleshoot > Advanced options > Startup Settings > Restart, then press 4 for Safe Mode or 5 for Safe Mode with Networking. From there you can remove the latest patch using the Windows Recovery tools described in the Windows Recovery Environment.
Mac: Open Safe Mode
Apple silicon: power off, then hold the power button until startup options load. Select your disk, hold Shift, and click Continue in Safe Mode. Intel Macs: power on, hold Shift until you see the login screen. Apple documents both methods in Start up your Mac in safe mode.
If Safe Mode works, back up key files now. Then remove the suspect update or driver and reboot normally.
Step 3: Use Recovery Tools To Undo The Update
Windows: Uninstall The Latest Patch From Recovery
From Windows Recovery, go to Troubleshoot > Advanced options > Uninstall Updates. Pick “Uninstall latest quality update” first. If the failure started after a version upgrade, use “Uninstall latest feature update.” You can also launch Startup Repair from the same menu if Windows won’t boot at all.
Windows: Restore A System Restore Point
Still stuck? In Advanced options, choose System Restore and pick a restore point dated before the update. This rolls back system files and drivers without touching personal files.
Mac: Use Recovery To Repair Or Reinstall
Shut down. Apple silicon: hold the power button to enter Recovery. Intel: hold Command-R at startup. Run First Aid in Disk Utility. If needed, reinstall macOS over the top; your data stays in place unless you erase the disk.
Step 4: Repair Boot Files
Windows: Fix The Boot Chain
Open the Command Prompt in Windows Recovery. Run Startup Repair first. If that fails, advanced users can run bootrec and sfc from the prompt to rebuild the boot configuration and repair system files. If you installed a new drive or changed partitions during the update, also check BIOS/UEFI boot order.
Mac: Select The Right Startup Disk
In Recovery, open Startup Disk and set the correct volume. If you see a prohibition symbol or a question mark folder, reconnect the internal drive or contact service if the disk has failed.
Step 5: When Nothing Else Works
A repair install keeps your files. On Windows, use “Reset this PC” and choose “Keep my files.” On a Mac, reinstall macOS over the top from Recovery. If storage errors appear, clone the disk first to protect data.
Windows Won’t Start After Update: Proven Paths
This section lays out exact routes that match the most common failure patterns.
Automatic Repair Loop
Open Recovery, run Startup Repair once. If it loops, uninstall the latest quality update. No change? Restore the most recent restore point. If still failing, run DISM and SFC from Command Prompt, then test boot.
Blue Screen With Reboot
Boot Safe Mode, roll back the display, storage, or network driver in Device Manager, then remove the update. Reboot and install a known-good driver package from the vendor.
Black Screen With Cursor
Press Ctrl+Shift+Esc to open Task Manager. If the shell didn’t start, run “explorer.exe.” If that works, remove the update from Settings. If not, go to Recovery and uninstall updates there.
macOS Won’t Start After Update: What Usually Works
Safe Mode Clears Bad Caches
Safe Mode runs checks and clears caches that can block login. If you reach the desktop, update third-party drivers and login items, then reboot normally.
Disk First Aid, Then Reinstall
Run First Aid on your startup volume and the container. If errors return clean, reinstall macOS over the top. Your user folder should remain intact. If First Aid reports disk faults, move to data rescue before any reinstall.
Firmware And Accessory Issues
Disconnect hubs and displays. If a Thunderbolt dock sits mid-chain, connect the display directly while testing. Reset NVRAM/SMC on Intel Macs. Apple silicon handles these resets automatically on each cold boot.
Data Safety: What Each Fix Touches
Most recovery actions keep personal files. The table below compares risk levels so you can pick the gentlest path first.
| Action | What It Changes | Personal Files |
|---|---|---|
| Safe Mode boot | Loads basic drivers only | Unaffected |
| Uninstall latest update | Removes last patch or version | Unaffected |
| System Restore (Windows) | Rolls back system files & drivers | Unaffected |
| Startup Repair (Windows) | Repairs boot files | Unaffected |
| Reinstall macOS over top | Replaces system files | Unaffected in normal case |
| Reset this PC: Keep my files | Refreshes Windows while keeping data | Kept; apps removed |
| Erase & clean install | Wipes disk and rebuilds OS | Erased |
How To Open Recovery When The Screen Is Blank
If the display stays black, use hardware keys. Windows laptops often expose a tiny reset hole near the hinge; press with a paper clip. Many desktops have a case reset switch. If you hear fans but see no video, test with another monitor or HDMI port, then attempt Recovery again.
Prevent The Next Post-Update Lockup
Keep 20–30 GB free on the system drive so feature updates have room. Update critical drivers from the vendor site, not only through the OS. Delay big updates for a week or two while early kinks surface. Make a restore point on Windows before Patch Tuesday. On a Mac, keep a Time Machine backup so you can roll back safely.
Decision Tree You Can Follow
Use this quick flow to pick your next step with confidence:
If There’s No Power
Swap outlets and cords. Try a known-good power brick. Remove the battery on older laptops, then hold the power button for a full 30 seconds. Refit the battery and try again.
If You See A Logo Loop
Force three failed boots to reach Recovery. Run Startup Repair once. If it returns to the loop, remove the latest quality update. Test boot again before moving on.
If Safe Mode Works But Normal Boot Fails
That points to a driver or a startup program. Remove the recent update and vendor drivers you just installed. Reboot, then add drivers back one at a time.
If Recovery Is Missing Or Broken
Create install media on another machine. Boot from it and select “Repair your computer” to reach the recovery menu. On a Mac, use another Mac to create a bootable installer, then start up holding Option to choose it.
When To Call A Pro
Signs of hardware trouble include repeating power clicks, burning smells, swollen batteries, and drives that vanish from Recovery. At that point, stop. Pull the disk if the warranty allows, or book a service visit so your data can be imaged safely. If you rely on the machine for work, arrange a loaner while repairs move forward.
After You’re Back In: Clean Up And Prevent
Windows Housekeeping
Turn on System Restore and create a manual restore point before big installs. Remove stale vendor utilities you no longer use. Keep firmware and BIOS from the PC maker current, as those updates often fix sleep and resume quirks. Leave a small pause on Patch Tuesday by choosing a seven-day update pause in Settings when stability matters.
Mac Housekeeping
Keep a current Time Machine drive connected on a schedule. Trim login items you don’t need under System Settings. If you use kernel extensions for audio or virtualization, update those installers first, then run the macOS update. Keep an installer on a USB stick so you can reinstall even if Wi-Fi is down. Test sleep, wake, and shutdown a few times before calling it done again today.