Before and after a clean reinstall: the checklist
What to capture before wiping a machine, and the 24-hour sequence that gets it back to working without losing a licence, a bookmark or a file.
Most reinstall disasters are not technical. They are the small things nobody wrote down: a licence key in an old email, a browser profile with saved logins, a folder on the desktop that was never included in the backup. The wipe itself is the easy part.
For the actual Windows and macOS reinstall walkthroughs, use our sister site ReinstallOS. This page is about everything that surrounds the wipe.
Capture these before you touch the installer
Export your browser bookmarks and confirm your password vault is synced and that you can unlock it from another device. Write down licence keys for anything paid, and photograph the list of installed programs so you have a reminder of what the machine used to do. Then check the folders people forget: Desktop, Downloads, the default save location of your editor, and any local mail archive.
Now make the backup and, crucially, open it. Copy a handful of files out of the archive or the external drive and verify they open. This is the step that turns a backup into evidence.
The tools this step calls for, with their real licence and platform details:
| Program | Licence / price | Platforms | Why it is on the list |
|---|---|---|---|
| Syncthing Publisher's site ↗ | Free · Open source | Windows, macOS, Linux, Android | Keeps folders identical across your own devices, peer to peer, with no cloud in the middle and no account. Because deletions propagate, it is synchronisation rather than backup. Pair it with versioning turned on. |
| FreeFileSync Publisher's site ↗ | Free · Open source | Windows, macOS, Linux | Compares two folders and shows you exactly what will be copied, moved or deleted before anything happens, then does it and verifies the result. The clearest free tool for mirroring to an external drive. |
| Duplicati Publisher's site ↗ | Free · Open source | Windows, macOS, Linux | Scheduled encrypted incremental backups to a local drive, a NAS or cloud storage, with a browser interface and retention rules. Good for a home setup. Test a restore before you trust it with anything. |
Make the bootable media carefully
Use the official image from the operating system publisher and a tool that verifies it. The single most destructive mistake in this whole process is selecting the wrong target disk when writing a USB stick: the tool will erase whatever you point it at, and there is no undo. Check the capacity and the drive letter against what you expect before starting.
The tools this step calls for, with their real licence and platform details:
| Program | Licence / price | Platforms | Why it is on the list |
|---|---|---|---|
| Rufus Publisher's site ↗ | Free · Open source | Windows | Writes a Windows or Linux ISO to a USB stick in a couple of minutes, faster than most vendor tools, and can bypass the Windows 11 TPM and account requirements if you ask it to. No install needed. |
| Ventoy Publisher's site ↗ | Free · Open source | Windows, Linux | Format a USB stick once, then just copy ISO files onto it and pick one from a boot menu. Replaces the whole reformat-burn-reformat cycle. Worth the twenty minutes of learning if you install systems regularly. |
The first 24 hours after the wipe
Updates and drivers first, then the browser, the password manager and the archive tool. Restore files before reinstalling applications, so you can see what you actually have. Then add programs one group at a time, using the machine between groups; if something breaks, you know which three installs to look at.
Leave the backup running for a week before you delete the old copy. A restore that looks correct on day one can still miss a folder you only open monthly.
The tools this step calls for, with their real licence and platform details:
| Program | Licence / price | Platforms | Why it is on the list |
|---|---|---|---|
| Firefox Publisher's site ↗ | Free · Open source | Windows, macOS, Linux, Android, iOS | The safest default for most people. It runs its own engine instead of Chromium, blocks trackers out of the box, and carries extensions the Chromium side is busy removing. Slightly rougher on a handful of Google properties. |
| Bitwarden Publisher's site ↗ | Free + paid tiers | Windows, macOS, Linux, Android, iOS | If you install one thing from this entire page, install this. The free tier covers unlimited passwords on unlimited devices with sync, and everything is end-to-end encrypted. Start here rather than with a paid competitor. |
| 7-Zip Publisher's site ↗ | Free · Open source | Windows, Linux | The first thing to install on any new PC. Unpacks everything, compresses better than WinRAR, and has never shipped a bundled toolbar in twenty-five years. Plain interface, zero nonsense. |
| WizTree Publisher's site ↗ | Free for personal use | Windows | Reads the master file table directly and shows you what is eating your disk in seconds, not minutes, with a treemap view. The fastest way to find the 40 GB you did not know you had. |
Mistakes to avoid
- Deleting the old backup as soon as the reinstall looks successful.
- Assuming cloud sync covered a folder that was only ever stored locally.
- Reinstalling every program from memory and ending up with a slower machine than the one you wiped.
Questions people ask
Do I need to deactivate licences first?
For some paid software, yes. Check the publisher's deactivation policy before wiping, or you may have to contact support to transfer the activation.
How long should I keep the old drive or image?
A fortnight of normal use is a sensible minimum. Long enough to open the monthly spreadsheet and the tax folder.
Related guides
Or see all guides and category explainers.
How to read this page. How to read this page. Platform, licence and publisher details come from our directory data. Where an independent review, audit or survey is mentioned, it is summarised in our own words with the source named and linked; our /sources page sets out that policy. The recommendation, the trade-offs and every 'skip it if' line are our editorial judgement. We do not run benchmarks, publish measured performance figures or host installers, and every download link goes to the publisher's own site. If a detail is out of date, our About page explains how to tell us.