I have been using JDK 9 on Windows 10 x64 for a while but when I went to install the latest early release (b174), I first uninstalled the previous version (as usual) and then ra
Try locating the lock file here:
%USERPROFILE%\AppData\LocalLow\Oracle\Java
Deleting it allowed my Java 10 installation to start.
I don't mean to be cheap but Control Panel > Uninstall a program > Java 9 is your friend
Control Panel
Uninstall a program
Java 9