If your secondary drive is encrypted with (common in business laptops) and you perform a clean install on the main drive without first backing up the BitLocker recovery key, the clean install will not wipe Drive D – but it will make Drive D permanently unreadable. Windows will show it as "RAW" or ask you to format it. To the average user, this looks wiped. It is not; it is locked.

The situation is slightly different when using the "Reset this PC" feature found within Windows settings. This is often mistaken for a clean install, but it offers more explicit choices.

But if you mean “does it wipe all drives without exception?” — , not by default. You’d need to explicitly delete partitions on other drives for that to happen.

This guide explains exactly how a clean install behaves, how to protect your secondary drives, and the steps to ensure a flawless installation. Understanding a Clean Install

During a standard clean install, you choose a to format and overwrite. The installer will only delete data on that chosen partition. The data on your other partitions or separate physical drives will remain completely untouched—provided you do not accidentally select them. The Risks: When a Clean Install Can Wipe Other Drives

Take note of the exact total size of each drive in gigabytes (GB). The setup menu displays drives by size, which helps you tell them apart. Step 3: Carefully Navigate the Installation Menu

It's crucial to understand that while your files on other drives will remain safe, many applications store critical data and configuration files on the system drive (C:). Even if you have installed a game or large software program to your D:\ drive, a clean install of Windows will wipe out all the registry entries and necessary data on the C:\ drive, which will likely break those applications. Therefore, you should plan to reinstall all your programs after a clean Windows installation.

Can I reinstall Windows 10 without losing my files? - Lenovo

During the "Advanced" setup, you are shown a list of all detected drives and partitions.

While the automated installer will not touch your other drives without permission, human error and complex drive configurations can lead to accidental data loss. User Error in the Partition Manager

If you want absolute peace of mind, disconnect your extra drives before you begin. It takes five minutes and guarantees your data stays completely safe.

In this exclusive deep-dive, we will separate fact from fiction. We will explain exactly what a clean install targets, which drives are safe, which are at risk, and how to perform a true "full wipe" if that is your goal.

If this is toggled to "Yes," Windows will wipe every secondary hard drive and SSD connected to the machine. How to Ensure Other Drives are Safe

Secondary drives use independent partition tables. The installer has no reason to modify these tables unless a user manually commands it to do so. Risks and Potential Scenarios for Accidental Data Loss

By doing this, it is physically impossible for the installer to touch, view, or accidentally wipe your secondary data. 3. Reconnect and Map Your Drives