A long time ago, I moved PortableApps.com and FirefoxPortable to my D drive. I did this because I also had OBSPortable installed and I could not get OBSPortable pinned to the taskbar from the USB Drive. Once I moved FirefoxPortable and OBSPortable to the D Drive, both would pin no problem. But this week, I uninstalled OBSPortable. I'm just using FIrefoxPortable now. And I want to install OpenOfficePortable too. I'd like to move both of these to my USB Drive, but I'm running into a problem where FirefoxPortable won't pin to the Taskbar from the USB Drive. Any idea why? I moved FirefoxPortable (and PortableApps.com) to an E drive, and it lets me pin from there. So D drive works. E drive works. But the G (USB Drive) doesn't. If I want my programs pinned, do they have to be on a non-USB drive?
This is a purposeful limitation within Windows itself if you're trying to drag the shortcut to an external drive. The way around this is to add it to the Start Menu first. Right-click it in the platform and select Add to Start menu. Then in the Start Menu, right-click it, select More, then select Pin to Taskbar.
Sometimes, the impossible can become possible, if you're awesome!