"java not found or recognized"

[hyakki]

have you tried starting Jpcsp as administrator?

Also make sure as said above your version matches jpcsp,
Java 32 bit should only be used with 32bit Jpcsp.
and Java 64-bit be used with the Jpcsp 64-bit.

You can quickly Identify what version you have installed by going to
(64bit OS)
C:\Program Files (x86)\Java\ = 32 Bit
C:\Program Files\Java\ = 64 bit

for a 32bit OS you can only install the 32bit one.