What a complete reset does and when you need one
A complete reset wipes your hard drive and reinstalls the operating system from scratch, removing all your files, programs, and settings. Your computer returns to the state it was in when it left the factory. This is different from a restart (which just reboots the system) or a refresh (which keeps some files but removes programs).
You might need a complete reset if your computer has become slow or unstable after years of use, if malware has infected it deeply, if you are selling or giving away the device, or if you want to start fresh with a clean installation. A reset also frees up disk space by removing accumulated clutter that even uninstalling programs does not always clear.
Before you reset, understand that this process is permanent and irreversible. Every file, every program, every photo and document will be gone unless you back it up first. The reset itself takes 30 minutes to several hours depending on your computer's speed and the size of your drive.
Key Takeaways
- Back up all your files to an external drive or cloud storage before starting, because a complete reset deletes everything on your computer.
- On Windows, use Settings > System > Recovery > Reset this PC; on Mac, restart and hold Command-R to enter Recovery Mode, then use Disk Utility and Reinstall macOS.
- You will need your Windows product key or Apple ID password to complete the reset and reactivate your operating system afterward.
- The reset process itself takes 30 minutes to several hours; do not interrupt it or unplug your computer while it is running.
- After the reset completes, you will need to reinstall all your programs and restore your backed-up files manually.
Back up your files before you start
The first and most critical step is to save everything you want to keep. Connect an external hard drive or USB drive to your computer and copy all your documents, photos, videos, and any other files you need. On Windows, your personal files are usually in C:\Users\[Your Username]\Documents, C:\Users\[Your Username]\Pictures, and similar folders. On Mac, check your Documents, Pictures, Downloads, and Desktop folders.
You can also use cloud storage services like Google Drive, OneDrive, or Dropbox to back up important files. Upload them while your computer is still working normally. This approach has the advantage that you can restore files from any device later, not just from an external drive.
If you have programs with settings or data you want to preserve—like browser bookmarks, email accounts, or game saves—export or save those separately. Most programs have an export or backup option in their settings menu. For example, Firefox and Chrome both let you export bookmarks as an HTML file.
Reset a Windows computer
On Windows 10 or Windows 11, the reset tool is built into the operating system. Open Settings by pressing the Windows key and typing "Settings," then click the Settings app. Navigate to System, then scroll down and click Recovery. You will see an option that says "Reset this PC"—click it.
Windows will ask whether you want to keep your files or remove everything. Choose "Remove everything" for a complete reset. The system will then ask whether you want to remove files and clean the drive. If you are selling the computer or giving it away, choose "Remove files and clean the drive" to make recovery of deleted data much harder. If you are keeping it, "Remove files" is sufficient.
Windows will show you a summary of what will happen and ask you to confirm. Once you confirm, the reset begins. Your computer will restart several times during this process. Do not turn it off or unplug it. When the reset finishes, Windows will show you the setup screen, just as if the computer were brand new. You will need to enter your Windows product key or sign in with your Microsoft account to reactivate Windows.
Reset a Mac computer
On a Mac, restart your computer and when ready hold down Command-R until you see the Apple logo or a spinning globe. This boots your Mac into Recovery Mode. You will see the macOS Utilities window with several options.
Click Disk Utility and select your main hard drive (usually called "Macintosh HD" or similar). Click the Erase button at the top, choose a format (APFS for newer Macs, Mac OS Extended for older ones), and confirm. This wipes the drive completely. When the erase finishes, close Disk Utility and return to the Utilities window.
Click "Reinstall macOS" and follow the on-screen prompts. The system will read and install a fresh copy of macOS. This process can take an hour or more depending on your internet speed. When it finishes, your Mac will restart and show the setup screen. Sign in with your Apple ID to reactivate macOS and restore your settings if you want to.
What to do if you forgot your password
If you cannot remember your Windows password, you can still reset your computer using a Microsoft account. On the Windows login screen, click "I forgot my password" and follow the recovery steps. You will need access to the email address or phone number associated with your Microsoft account. If you do not have that access, you may need to use a password reset disk (if you created one previously) or contact Microsoft support.
On a Mac, if you forgot your login password, restart into Recovery Mode (Command-R) and use the Reset Password utility from the Utilities menu. You will need your Apple ID and password. If you do not have access to your Apple ID, you may need to contact Apple Support or visit an Apple Store.
Reinstall your programs and restore your files
After the reset completes and your computer boots up for the first time, you will have a clean operating system with no programs except the ones that came with it. You will need to reinstall everything you use. read your programs from their official websites or from the Microsoft Store (Windows) or App Store (Mac).
Restore your backed-up files by connecting your external drive or signing into your cloud storage account. Copy your documents, photos, and other files back to their original locations. This is also a good time to organize your files and delete anything you no longer need.
Reinstalling programs one by one takes time, but it gives you a chance to remove software you no longer use. You might find that your computer runs faster and more smoothly with only the programs you actually need.
Troubleshooting common reset problems
If your reset gets stuck or fails partway through, try restarting your computer and running the reset again. Make sure your computer is plugged in and has at least 20 percent battery if it is a laptop. A low battery can cause the reset to fail.
If Windows will not boot into Recovery Mode, you can create a Windows installation media on another computer using the Windows Media Creation Tool (available from Microsoft's website). read it, run it on a working computer with a USB drive connected, and follow the prompts to create bootable media. Then plug that USB drive into the computer you want to reset, restart, and boot from the USB drive to begin the reset process.
If a Mac reset fails, try restarting into Recovery Mode again and using Disk Utility to repair the drive before erasing it. If problems persist, contact Apple Support or visit an Apple Store, as hardware issues may be preventing the reset from completing.
Frequently Asked Questions
Can I undo a reset after it is done?
No. A complete reset is permanent. Once the process finishes, all your files and programs are gone. This is why backing up before you start is so important. If you realize you need something after the reset, your only option is to restore it from a backup you made beforehand.
Do I need my product key to reset Windows?
If you are using a Microsoft account, Windows will reactivate automatically when you sign in after the reset. If you are using a local account, you will need your Windows product key. If you do not have it, you can find it on the original packaging, in your email confirmation, or by contacting Microsoft support.
How long does a complete reset actually take?
The time varies widely. On a fast computer with a solid-state drive, a reset can finish in 30 to 45 minutes. On an older computer with a traditional hard drive, it can take two to three hours. The read and installation of the operating system is the longest part, so a faster internet connection helps.
Will resetting my computer remove viruses?
Yes. A complete reset removes all files and programs, including malware. However, if malware is on an external drive or cloud storage account you use, it could reinfect your computer after the reset. Scan any external drives with antivirus software before connecting them to your freshly reset computer.
What if my computer will not turn on at all?
If your computer will not boot, you cannot use the built-in reset tools. You will need to create bootable installation media on another computer (using the Windows Media Creation Tool for Windows or the macOS installer for Mac) and boot from that. If you are not comfortable doing this, contact a local computer repair shop, as the problem may be hardware-related rather than software-related.