You cannot (and should not) download javaw.exe alone. It is part of the Java Runtime Environment.
where javaw If a path appears, you already have it. No download needed. Title: Where to safely download javaw.exe? javaw.exe download
Run the installer. By default, it installs to: C:\Program Files\Java\jre1.8.0_401\bin\javaw.exe You cannot (and should not) download javaw