Java on a PC without Admin rights

This has probably been asked before but I cannot find it anywhere.
I have a PC without Admin rights and no Java installed.
I have downloaded and unpacked the portable version of Portfolio Performance and, as I got the error “no java virtual machine was found in \portfolio\jre\bin\javaw.exe” I downloaded jre from portableapps.com and move the content to the PP directory. Now the error is “failed to load the JNI shared library jvm.dll” even if the file is where PP expects to find it.
Do you know how to solve the problem ?