Unfortunately the only way I’ve been able to reproduce this issue is when powershell.exe is not available in the PATH. Part of the process above checked this, so if that was followed then there are only a handful of options. Anti-malware is a possibility, but I’d expect access denied errors instead.
That said, there is an update on the way soon which will at the very least provide us with more information to track this down. Edit: It is more likely that it will resolve the issue.
Stop reading here if you’re happy to wait for the next release (recommended).
Manual troubleshooting steps
You can also try completely uninstalling and reinstalling.
Purely to test, you can select CPU mode (which reduces total download to around 300MB), then pick a completely new location to install to. Delete %APPDATA%\config.json and %APPDATA%\extra_models_config.json if it works (will allow you to select your old install dir).