Key takeaway: A proper backup takes less than an hour for most home users and removes essentially all risk from trying Linux — never skip this step, even if you only plan to dual-boot.
Before installing Linux, trying a dual-boot setup, or even just testing a distribution from a USB stick, taking a proper backup of your Windows PC is the single most important step. It costs a little time now and removes almost all the risk of the process, whatever happens next.
Before you start: Even if you only plan to try Linux temporarily from a USB stick without installing anything, back up first. Mistakes during partitioning or installation, though uncommon, do happen, and a backup means nothing is ever genuinely at risk.
What to back up
Focus on anything that cannot easily be redownloaded or recreated: documents, spreadsheets and PDFs in your Documents folder; photos and videos, especially anywhere outside of automatic cloud backup; music you have purchased or ripped yourself; and any files saved directly to your Desktop. It is also worth exporting browser bookmarks and checking that saved passwords are backed up through your browser's built-in sync (Firefox or Chrome accounts both handle this automatically once signed in).
- Plug in an external USB drive or hard disk with enough free space for your files — a quick way to check your total usage is to open File Explorer, right-click your main drive, and select Properties.
- Open File Explorer and navigate to your user folder (usually C:\Users\YourName), which contains Documents, Pictures, Videos, Music, Desktop and Downloads.
- Select these folders and drag them onto the external drive, or use Windows' built-in "Backup and Restore" or "File History" tool under Settings for a more automated copy.
- Separately, sign into your browser account (Firefox Sync or your Google account in Chrome) to confirm bookmarks and saved logins are backed up to the cloud, not just stored locally.
- If you use cloud storage such as OneDrive, Google Drive or Dropbox, make sure recent files have fully synced online, not just marked as "available offline" on this one PC.
- Once copied, open a few files directly from the external drive to confirm they open correctly — a backup is only useful if it actually works.
Backing up program settings and licence keys
Some programs store licence keys or activation codes locally rather than tied to an online account. If you rely on paid software with a product key, locate and note that key before wiping Windows — many programs show it under Help > About, or you can use a free key-finder utility if the key is not otherwise recorded anywhere.
Tip: Take a few photos or screenshots of any custom settings, browser extensions, or configurations you would want to recreate — small time-savers that are easy to forget once the machine has moved on.
Backing up your whole Windows installation (optional)
If you want a full safety net rather than just your personal files, consider creating a complete disk image using free software such as Macrium Reflect Free, which lets you restore your entire Windows setup exactly as it was, including installed programs, if you later decide Linux is not for you and want to return to a single-boot Windows PC.
Frequently asked questions
- Do I need an external drive, or can I use cloud storage instead?
- Either works well; cloud storage is convenient if your files fit within a free or existing paid tier, while an external drive is faster for large amounts of data such as photo and video libraries.
- How much free space do I need for a backup?
- Enough to hold your personal files, typically shown under your C: drive's Properties in File Explorer — most home users need somewhere between a few gigabytes and a few hundred, depending mainly on photo and video collections.
- Should I back up even if I am only dual-booting, not replacing Windows?
- Yes. Partitioning carries a small inherent risk, and a backup ensures that even an unlikely mistake during setup cannot cost you anything important.