While the default behavior is safe for secondary drives, you can deliberately or accidentally wipe everything under two conditions:
If you are using a laptop or cannot easily disconnect your internal drives, rename them beforehand so you can easily identify them during setup. Open in Windows File Explorer. Right-click your secondary drive and select Rename . Give it a distinct name, such as "Data_Drive" or "Backup".
If you accidentally select the wrong drive, delete the wrong partition, or choose to format all listed drives, you will lose your data. Distinguishing between multiple drives can be difficult on this screen because they are often identified only by their total size and unallocated space, rather than their volume names (like "Entertainment" or "Backup"). Step-by-Step Guide to Safeguarding Your Data
The most common cause of accidental wiping is selecting the wrong drive during the installation process. The Windows setup screen shows a list of available drives and partitions (e.g., Drive 0 Partition 1, Drive 1 Partition 1). If your drives are not clearly labeled, you might accidentally format your secondary data drive thinking it is your system drive. 2. Deleting All Partitions does clean install wipe all drives exclusive
If you are using a desktop PC or a laptop with easily accessible storage slots, before turning on the computer to run the installer.
Are you trying to or just speed up the machine ?
While the installer focuses only on the target drive, user error during the setup partition screen is the leading cause of accidental data deletion on secondary drives. Why Secondary Drives Are at Risk (and How to Avoid It) While the default behavior is safe for secondary
If your Drive D is a partition on the same physical hard drive as Drive C (e.g., a 1TB drive split into C: 500GB and D: 500GB), then a clean install using the "Delete partition" function will wipe both C and D because they are on the same physical disk.
A clean installation of an operating system, such as Windows, does not automatically wipe all drives
A "clean install" does automatically wipe all drives; it typically only affects the specific drive or partition you choose during the setup. However, some automated recovery methods, like a "Reset this PC," can be configured to wipe every connected drive. Clean Install vs. Reset Give it a distinct name, such as "Data_Drive" or "Backup"
Internal hard drives (HDDs), secondary solid-state drives (SSDs), and external storage devices remain completely untouched by the installer, provided you do not manually format them. Why Secondary Drives Are at Risk During a Clean Install
The core principle of a true clean install is that it will wipe the specific drive and partition where you choose to install the operating system. This is done by deleting all existing partitions on that drive, turning it into a blank slate of "unallocated space," and then creating the new system partitions required for Windows to run.
While the process is exclusive to the drive you select, human error is the biggest threat.
A clean install is an excellent tool for optimization. By slowing down during the partition selection process or physically disconnecting your secondary hardware, you can enjoy a fresh, fast operating system without losing a single megabyte of your personal data.