Rightclick on the taskbar (that's the name) and add this particular toolbar (something like language bar, I think, but I don't have the English version of the OS).
It's not a control panel thing.
My Windows Vista system used to allow me to change languages by clicking on an icon in the lowere tool bar. The icon has disappeared. Yes, I have gone to control panel and selected languages and regions. English and Russian are there but the icon rfuses to appear in the tool bar.
What went wrong???