"main class could not be found, program will exit!"

JVM Launcher - "Cannot Find main class" on install of Oracle Enterprise Edition [ID 244132.1]

Symptom(s)
~~~~~~~~~~
Running setup.exe from disk1 results in JVM Launcher dialog with error message: 
"main class could not be found, program will exit!"


Cause
~~~~~~~
The Oracle Universal Installer version supplied with 9.2.0.1 RDBMS Enterprise 
Edition, copies the expanded OUI classes and JRE (v1.3.1.1.0a) from the distribution 
media (Disk1\stage\Components\oracle.swd.jre\1.3.1.1.0a) to the current user's 
TEMP directory as defined by :

   HKEY_CURRENT_USER\Environment\TEMP
   and/or
   HKEY_CURRENT_USER\Environment\TMP

in the registry. This is likely to be something like :

   C:\Documents and Settings\\Local Settings\Temp

Then it builds a command line to invoke the JRE and start the 
main OUI class. This command line includes the -CP switch to JAVAW.EXE that 
specifies the CLASSPATH for the JRE. This CLASSPATH will contain the directory 
specified in HKEY_CURRENT_USER\Environment\TEMP amoungst others.

If the directory specified by HKEY_CURRENT_USER\Environment\TEMP contains a hash 
symbol, #, then when the JVM comes to parse the dynamically built CLASSPATH it 
will fail and be unable to load its core classes from rt.jar - hence the error.

The default directory specified by HKEY_CURRENT_USER\Environment\TEMP is :

   %USERPROFILE%\Local Settings\Temp

%USERPROFILE% is an OS envrionment variable and will contain the OS user name.
The cause was discovered when using a username with a hash symbol in it, i.e. 
#dba, resulting in a path like :

   C:\Documents and Settings\#dba\Local Settings\Temp

Fix
~~~~

Change :

  HKEY_CURRENT_USER\Environment\TEMP
  and/or
  HKEY_CURRENT_USER\Environment\TMP

to point to c:\temp or some other writable directory path with no special 
characters.  
(NOTE:  Make sure the directory exists, before assigning the directory).



References
~~~~~~~~~~~
Other install issues :
Note:137200.1 Checklist when Oracle Universal Installer (OUI) fails for Windows