The iPhone 5s is a 64-bit device. Some older downgrade tools (like Odysseus) were designed for 32-bit devices (iPhone 5). You must use tools compatible with 64-bit checkm8 exploits (like futurerestore ).
Most specialized downgrade tools, like , are designed for macOS or Linux because Windows has difficulty handling the low-level USB communication required for "pwned DFU" mode. However, Windows users can still achieve this downgrade by using a Linux Live USB (such as Ubuntu) to run these tools without replacing their Windows installation. Method 1: The "Linux Live USB" Workaround (Most Reliable) iphone 5s downgrade to 10.3.3 windows
Downgrading an iPhone 5s to iOS 10.3.3 on Windows remains a popular request for users seeking better performance or 32-bit app compatibility. While Apple stopped "officially" signing this version via iTunes years ago, a unique loophole allows the iPhone 5s (and other A7 devices) to downgrade to iOS 10.3.3 because it remains signed as an for life. Can You Downgrade Directly on Windows? The iPhone 5s is a 64-bit device