You install 64 bit JRE, you install the Cisco ASDM client, you try to run it, but it won’t start. Then you might as well try to start it from the command line:
java -jar asdm-launcher.jar
Then you get this:
Exception in thread "main" java.lang.ExceptionInInitializerError at com.cisco.launcher.s.if(Unknown Source) at com.cisco.launcher.Launcher.main(Unknown Source) Caused by: java.lang.ArrayIndexOutOfBoundsException: 1 at com.cisco.launcher.ClassUtil.<clinit>(Unknown Source) ... 2 more
Guess what, ASDM still doesn’t support 64-bit Java. That’s particularly worrisome because the latest release of Java is 64-bit only.
Anyhow, your best bet is to install 32-bit JRE 8. Problem “solved”. And shame on you, Cisco.