A grab-bag of one-liners that come up often enough to keep handy.

Force an immediate reboot

shutdown /f /r /t 0

PsExec — remote command execution

psexec \\computername cmd
psexec \\computername -u domain\user -p password cmd
psexec \\computername powershell enable-psremoting -force

See also: AnyDesk for remote access without PsExec.