When I run a executable file, I am gettibg a error message. ' Java Virtual Machine Launcher ' - Could not find the main class.Program will exit.

Can any provide me the solution what the problem maybe?
Orelse should I install any software to rectify it?

This will reinstall the JVM and hopefully fix the problem.
Use the CONTROL PANEL > ADD/REMOVE PROGRAMS to uninstall all the Java components listed.
Reboot.
Go to http://cds.sun.com/is-bin/INTERSHOP.enfinity/WFS/CDS-CDS_Developer-Site/en_US/-/USD/VerifyItem-Start/jre-6u6-windows-i586-p-iftw.exe?BundledLineItemUUID=.HRIBe.mfe0AAAEajZNVg FI3&OrderID=nfdIBe.mT00AAAEagpNVgFI3&ProductID=fU5IBe.nalwAAAEZyWklHgvk&FileName=/jre-6u6-windows-i586-p-iftw.exe
If you are prompted with a Save/Open dialog - press open.
Wait for this download to finish
The program should then run automatically
Follow the onscreen instructions and install the JRE.
Reboot the computer.
Try your java programs now