The following file was built using mxe: picotool.exe
It has been tested to work on Windows 7, 10 and 11.
It doesn't work on Windows XP.
You will need to download and run zadig:
You will want to select "RP2 Boot (Interface 1)" in the dropdown, and install the "WinUSB" driver.
After that you can run picotool on the command prompt.