Today, I downloaded latest version of Jenkins (1.540). I have Java 1.7.0_45 installed on Windows 7.
When I start Jenkins:

java -jar jenkins.war

it looks as it is starting and when the last message appears:

INFO: Jenkins is fully up and running

a message pops up saying: Java platform binary has stopped working and I can't connect to localhot:8080.

I looked up this in the Internet and I found one similar issue reported on StackOverflow:
http://stackoverflow.com/questions/20085795/java-tm-platform-binary-has-stopped-working-pop-up-arrived-during-starting-jekin

This has been reported 13 hours ago from now (14:55 GMT).

I tried to run Jenkins (1.540) on two different Win7 machines and on both it was crashing Java.

I found a quick solution - simply use previous build of Jenkins (1.539). This one looks to be working fine (or at least it doesn't crash Java and I can connect to localhost:8080).