How to Fix Ora-12519 No Appropriate Service Handler Found

I often encountered this error after setting up a new machine with jboss/seam/oracle project installed.

To resolve this:
1.) Open command prompt, by typing cmd in Start
2.) Execute c:\windows\system\sqlplus system@YOUR_SID
3.) Execute "ALTER SYSTEM SET PROCESSES=150 SCOPE=SPFILE;"

Then restart the oracle database or your computer.