A clean install does automatically wipe all drives ; it typically only affects the specific drive or partition you select for the operating system installation. While it "cleans" the target location by removing existing system files and applications, other physical drives and separate partitions generally remain untouched unless you manually choose to format or delete them during the setup process. How Drives Are Affected

Step 5: Select the unallocated space and click Next.

Headline: The Critical Truth: Does a Clean Install Really Wipe All Drives? (No, But It’s Dangerous)

Windows will now create new partitions and install the OS exclusively on that unallocated space.

When you perform a clean install, you are essentially starting with a "blank slate" for the operating system. However, the scope of that slate is largely under your control: