Cause: Missing Windows updates (KB4474419 and KB4490628).
Fix: Reinstall the two SHA-2 updates manually from Microsoft Catalog. Reboot twice.
As of late 2023, running a "full" and secure version of Tor Browser on Windows 7 32-bit is technically possible but highly inadvisable.
While legacy versions of the Tor Browser will function on this operating system, the Tor Project and its underlying engine (Mozilla Firefox ESR) have officially dropped support for Windows 7. Consequently, users running Tor on Windows 7 32-bit face a paradox: they are using a tool designed for ultimate privacy on an operating system that is inherently insecure and no longer receives security patches. tor browser for pc windows 7 32bit full
After launching, do the following:
Disable JavaScript globally (for maximum anonymity): Tor Browser for Windows 7 (32-Bit): Full Guide
Never maximize the browser window. Many websites track window size; a maximized 1366×768 resolution is unique. Use default ~1000×800 size.
No browser plugins: Tor Browser disables Flash, Java, ActiveX, and WebGL by default. Keep it that way. Never install additional add-ons. Disable JavaScript globally (for maximum anonymity):
Update manually (since auto-update is broken on Win7 for newer versions):
The default path is C:\Users\[YourName]\Desktop\Tor Browser. You can change it, but avoid Program Files (x86) (that’s for 32-bit apps on 64-bit systems; here, it's fine actually, but Desktop is simpler).
Tip for low-space Windows 7 32-bit: Install to a USB stick or secondary partition.