Opatch problem - client VM not supported, error 1

I have problem with trying to patch Oracle 11.2.0.1.1 to 11.2.0.1.13 on Windows 2008 R2 (all 64-bit).

I downloaded the right opatch utility (11.2.0.5) and extracted all files to ORACLE_HOME/Opatch folder.

When I run opatch, it gives me the following error:

C:\oracle\product\11.2.0\db_cs\OPatch>opatch
Error: client VM not supported

OPatch failed with error code = 1

 

I guess this is a Java related problem (opatch needs Java 1.5.0 which is installed in Oracle home, but there is also a higher version installed not by Oracle):

C:\oracle\product\11.2.0\db_cs\OPatch>java -version
java version "1.6.0_22"
Java(TM) SE Runtime Environment (build 1.6.0_22-b04)