I found a thread below that may or may not help. Please be careful if try out the regedit thing because messing with the registry can be very dangerous.
http://forum.feed-the-beast.com/threads/why-ftb_launcher-always-run-java-32-bits-as-default.6171/#post-367123
I am not entirely sure if this will work but it is worth a shot. If it still does not work then my only thinking is that something has gone wrong with windows.
I tried the revo uninstaller myself and it did not detect my java either.It also missed out other programs not just java.
@Ashzification is it worth asking any of the other tech support guys if they have any solutions for this problem.

is it normal ?
Edit:This java problem reaveled when i play terraria with friends terraria crashed and ftb ram go down to 1gb all java things doesnt work