Written 3 Sep 2026. This is a how-to, not a product card.

Wipe a Marketplace PC before you install

A used OptiPlex may still have the last owner's Windows and logins. Wipe the disk with the installer before you plug it into the house network.

Haven't found a computer yet? Start with what you already have. Haven't chosen an OS? See what OS to put on it. The install weekend itself is your first weekend. This note is the wipe before that weekend.

Skip until you have a used PC to dedicate

If you don't have a used computer you plan to leave on — Marketplace, buy-nothing, or a closet OptiPlex — stop. That is start with what you already have. Skip this note if the machine is still your daily Windows laptop. Leaving Windows on a daily driver is what OS to put on it, not a wipe.

What this is

Wiping means the Ubuntu Server or Debian installer overwrites the whole internal disk. Old Windows, old accounts, and old files go away. You don't need DBAN or a shredder for a home-lab box you keep. The installer is enough.

Don't plug the house cable first

Leave ethernet unplugged. Skip joining house Wi-Fi. Do this until the fresh OS is on. An old Windows with someone else's accounts does not belong on the house network, even for "just a look."

Copy off anything you still want

Rare on a Marketplace box, but if there are photos or papers you care about, copy them to a USB stick first. If the computer is empty, skip this step.

Make the USB installer

Download Ubuntu Server or Debian from the official site only. An 8 GB stick is enough.

Write the ISO with balenaEtcher or Ventoy. On Windows, Rufus is fine if you already have it. Flash the stick. Don't drag the ISO onto it in Explorer. That does not make a bootable installer. Full stick walkthrough: make a boot USB for the install.

Boot from the USB

Power on and tap F12, F10, or Esc (Dell often uses F12). Pick the USB stick from the boot menu. Enter the installer.

Wipe during install

Pick the whole internal disk. Use guided install / use entire disk (or erase disk). One disk is fine. Don't dual-boot with leftover Windows on a Marketplace box. Create your own user. Enable the OpenSSH server checkbox if Ubuntu offers it.

After install

Remove the USB stick. Reboot into the new OS. Then plug ethernet. Continue with your first weekend — find the address, SSH from the couch, update, leave it on. If you already finished that shape, next is find it on the house network and SSH from the couch.

If you already installed Linux but left old accounts

That look is see if the computer still has old login accounts — locking leftovers. Prefer a wipe for a Marketplace box when you can.

What this is not

This is not a reason to buy a new N100. It is not a secure-erase lecture for selling the disk. It is not BitLocker recovery theater. If the disk is BitLocker-locked and you have no key, the installer still overwrites when you wipe the whole disk.

What next

After the wipe, do the install weekend: your first weekend. If you still need to pick Debian or Ubuntu Server, see what OS to put on it. Once it is on the house network, find it, then SSH from the couch.

Skip

• Skip plugging into the house network before the wipe.
• Skip keeping dual-boot Windows on a Marketplace box.
• Skip DBAN or a shredder for a computer you keep.
• Skip buying a new mini PC because the wipe felt scary.
• Skip this if it is still your daily laptop.