I am using Eclipse Helios, till yesterday my eclipse was working fine.
However today when I am trying to start I am unable to start my eclipse by double click on eclipse.exe.The eclipse Helios page appears for 1 second and then goes
Its very difficult to figure out the problem. You can check the eclipse logs that are generated in folder where eclipse is installed or in the workspace which you are tries to open. It might happen that some plugin got corrupted while closing the workspace.
Try opening a command prompt and that running eclipsec.exe. That might give some more clues as to the problem.
Also, double-check your eclipse.ini. A misconfiguration (such as referencing a JVM that is no longer on your system because you upgraded) can cause this behavior.
If you still have a problem, then reinstall and be very careful about what plugins you install!