Does C:\Program Files\Java\jdk1.6.0_16\jre\lib\rt.jar exist?
Try adding -verbose:class as the last lin in eclipse.ini and run eclipsec.exe instead. Run it from the command line and redirect the output to a file:
Make sure you run Eclipse to the point where it generates those errors. Then zip up the output.txt file and attach it to you response.
By the way, two suggestions:
1) Upgrade to a more recent version of the JDK 1.6.0_16 is really old, you should try 1.6.0_26 or higher.
2) Don't install into Program Files. Spaces in path names cause all kinds of strange problems.