Try changing the path to your java path instead of the minecraft runtime.
It should be in OS DISK> Program files and then find java and inside there look after the javaw.exe
If you have further questions on how to do this feel free to contact me. ;)
On windows, minecraft downloads its own version of java. So I'd recomment reinstalling minecraft. If he reinstalls the regular java, he'll also have to do what ElPatricko said for it to have any effect.You can try reinstalling your Java. If that isnt working you can take a look in your java path. If it is still not working you can try to use to old launcher you can download it here
okii locking this thread :)@Marieke2001, @Anmazing. Lock as the problem has been solved?