What to back up before reinstalling Windows
Before you reinstall Windows, you need to back up three things: your personal files (documents, photos, videos), your program settings and data (browser bookmarks, email accounts, game saves), and a list of which programs you have installed so you can reinstall them afterward. A fresh Windows install wipes your hard drive clean, so anything not backed up will be gone. The safest approach is to back up to an external drive — a USB drive for small amounts of data, or an external hard drive if you have a lot of files.
You do not need to back up Windows itself or the programs you have installed. Windows will be brand new after the install, and you will reinstall your programs from their original sources (Microsoft Store, Adobe's website, Steam, and so on). What you are protecting is the stuff only you have: your photos, your documents, your browser history, your saved games, your email messages.
Key Takeaways
- Back up your Documents, Pictures, Videos, and Desktop folders to an external drive before you start the reinstall process.
- Export your browser bookmarks and passwords from Chrome, Firefox, or Edge so you can import them into the fresh Windows install.
- Write down which programs you use regularly (or take a screenshot of your installed programs list) so you know what to reinstall.
- Disconnect your external backup drive after the backup is complete so it does not get wiped if something goes wrong during the install.
- A fresh Windows install takes one to three hours depending on your internet speed and how many programs you need to reinstall.
Back up your personal files to an external drive
Plug in your external drive and let Windows recognize it. Open File Explorer (the folder icon on your taskbar), and on the left side you will see your user folder — it usually shows your name. Inside that folder are Documents, Pictures, Videos, Desktop, and Downloads. These are the folders that hold your personal files.
Select all four folders (Documents, Pictures, Videos, and Desktop) by clicking the first one, then holding Ctrl and clicking the others. Right-click and choose Copy. Navigate to your external drive in File Explorer, right-click in the empty space, and choose Paste. This will take anywhere from a few minutes to several hours depending on how much data you have. Do not unplug the drive while the copy is running — wait until the progress bar finishes and disappears.
If you have files in your Downloads folder that you want to keep, copy that folder too. Many people leave Downloads empty after they install programs, so check first. You can also back up your Desktop separately if it has files on it that are not in Documents.
Export your browser bookmarks and passwords
Your browser bookmarks, saved passwords, and browsing history live inside your browser program, not in your Documents folder. You need to export them separately so you can bring them into the fresh Windows install.
For Microsoft Edge: Click the three-dot menu in the top right corner, go to Settings, then Profiles, then Export profile data. Choose which data you want to export (bookmarks, passwords, browsing history, payment info). Select your external drive as the destination and click Export.
For Google Chrome: Click the three-dot menu in the top right, go to Settings, then Autofill and passwords on the left side. Click the three dots next to "Password Manager" and choose Export passwords. Chrome will ask you to confirm your Windows password, then save a file to your Downloads folder. Move that file to your external drive. For bookmarks, go back to Settings, click Bookmarks on the left, then the three dots next to "Bookmark manager" and choose Export bookmarks.
For Firefox: Click the menu button (three horizontal lines) in the top right, go to Bookmarks, then Manage Bookmarks. In the window that opens, click the gear icon and choose Export Bookmarks. Save the file to your external drive. For passwords, go back to the menu, click Settings, then Privacy & Security on the left. Scroll down to "Logins and Passwords" and click Saved Logins. Click the three dots and choose Export Logins.
Create a list of your installed programs
You will need to know which programs to reinstall after Windows is fresh. The easiest way is to take a screenshot of your installed programs list right now, so you have a reference when you are setting up the new system.
Right-click on the Windows Start button and choose Installed apps (or Apps and features on older Windows versions). You will see a list of everything installed on your computer. Scroll through and take a screenshot of each page — use the Print Screen key, then paste the image into Notepad or Paint and save it to your external drive. This gives you a visual record of what you had.
Alternatively, write down the names of the programs you use most: your web browser, your email client, Microsoft Office or a free alternative, any creative software, any games, any work-related programs. You do not need to reinstall every single program — just the ones you actually use. Many programs you see in that list came with Windows or are not things you need.
Back up your email and chat accounts
If you use Outlook, Gmail, or another email client on your computer, you should export your email messages and account settings before the fresh install. If you only use email through a web browser (like Gmail in Chrome), you do not need to do this — your email will be waiting for you online when you log back in.
For Outlook: Open Outlook, click File in the top left, then Open & Export, then Import/Export. Choose Export to a file, select Outlook Data File (.pst), and choose which folders to export (usually your entire mailbox). Save the file to your external drive.
For chat programs like Discord, Slack, or Teams, your messages are stored on the company's servers, not on your computer. You do not need to back them up — they will be there when you log back in after the fresh install. The same is true for cloud services like OneDrive, Google Drive, and Dropbox. Those files live in the cloud, not on your hard drive, so they are already safe.
Check your backup before you start the install
Before you begin the Windows reinstall, verify that your external drive has everything you need. Open File Explorer, navigate to your external drive, and confirm you can see your Documents, Pictures, Videos, and Desktop folders. Check that your browser export files are there. Make sure your Outlook backup file (if you created one) is visible.
This is your final note to catch a problem. If something did not copy correctly, you can fix it now. Once you start the Windows reinstall, your hard drive will be erased, and you will not be able to recover anything that did not make it to the external drive.
After you have confirmed everything is there, disconnect your external drive and set it aside in a safe place. Do not leave it plugged in during the Windows install — if something goes wrong, you want your backup to be completely separate from your computer.
What to do after the fresh install
Once Windows is installed and running, plug your external drive back in. Open File Explorer, navigate to your backup drive, and copy your Documents, Pictures, Videos, and Desktop folders back into your new user folder. Then reinstall your programs one by one from their official sources. Import your browser bookmarks and passwords using the export files you saved. If you backed up Outlook, import that .pst file into the new Outlook installation.
The fresh install will feel empty at first, but as you restore your files and reinstall your programs, your computer will look and feel like it did before — except faster and cleaner, because you have removed years of accumulated junk.
Frequently Asked Questions
Do I need to back up my entire hard drive, or just my personal files?
Just your personal files. Windows and all your programs will be brand new after the install, which is the whole point. Backing up the entire drive would include all the old system files and program remnants that are slowing your computer down. Back up only Documents, Pictures, Videos, Desktop, and your browser and email exports.
Can I back up to cloud storage like OneDrive or Google Drive instead of an external drive?
Yes, if you have enough space and a fast internet connection. Upload your Documents, Pictures, Videos, and Desktop folders to OneDrive or Google Drive, and they will be waiting for you after the install. This is actually safer than an external drive because you have a copy in the cloud. The downside is that uploading large amounts of data can take hours.
What if I forget to back up something before I start the install?
Once the Windows install begins, anything not backed up is gone. There is no recovery option. This is why the backup step is so important — take the time to do it thoroughly, even if it feels slow.
Do I need to back up my Windows license or product key?
No. Windows 10 and Windows 11 are tied to your Microsoft account, not to a physical key. When you reinstall Windows and sign in with the same Microsoft account, Windows will recognize your license automatically. If you have an older version of Windows with a physical product key, write down the key before you start, but you do not need to back up anything else related to it.
How long does a fresh Windows install take?
The install itself usually takes 20 to 45 minutes. After that, you will spend one to three hours reinstalling your programs and restoring your files, depending on how much you have and how fast your internet is. Plan for a full afternoon or evening.