Windows 10 Creators Update (April 2017, version 1703) appears to have problems with Raster fonts in PowerShell and Command Prompt windows: launching either of these programs will show complete junk instead because the contents are readable.

The normal DISM and SFC tools don’t help here, but the repair is straightforward.

First, open PowerShell or Command Prompt. Then open the window’s shortcut menu by clicking the small icon in the top left or using the keyboard shortcut ALT + SPACE.
Choose Properties from the menu.

In the Properties window, open the Font tab and choose anything except Raster Fonts (the cause of all evil in this case). Consolas in sizes 14-16 usually works best.
Click Ok and see the miracle: Windows PowerShell or Command Prompt has lost the code, and you can read the window contents! 😀

Update: please note that font settings for Lucida Console will not persist on reboot. This is a too long Microsoft bug, so please use the Consolas font here.

Please note that this setting is retained only until shutdown or restart. To permanently edit the setting, reopen the window’s shortcut menu by clicking the small icon in the top left or with the keyboard shortcut ALT + SPACE. This time, choose Defaults from the menu and repeat the font change process (but don’t choose the Lucida Console font as explained above).

It’s like the fastest fix in the history of Microsoft Windows! But it looks like this bug is on Microsoft’s side, as SFC and DISM don’t fix Raster Fonts.