Launcher crashing and giving error message shortly after starting launcher

[EliteBeat02]

Launcher Version: Unknown

Operating System: Windows 7

Java Version: 6

Antivirus Program: Windows Defender

Description of Problem:

When I start the launcher, it comes up with the technic launcher logo and the green bar under it. When the green bar goes to about 20%, it stops and give an error message, "Could not find the main class: org.spoutcraft.launcher.entrypoint.Start. Program will exit."

Error Messages:

Java virtual machine launcher : "Could not find the main class: org.spoutcraft.launcher.entrypoint.Start. Program will exit."

Error Log:

[CreeperGoBoom]

you need to update your java, first, download java 7 update 45 (if you have a 64bit version of windows (more than 2GB ram) then search and download "java 7 x64 update 45 download")

then, remove your current version of java, reboot

install the new version, reboot (this is a necessary step to register the new installation of java fully)