GeneXus - PROBLEMA CON REORGANIZACION

Buenas estoy re - instalando GX 9 POSTGRESQL 8.3 + JAVA en MAQ Virtual (WINDOWS XP)
Ya tengo el proyecto, cuand le doy reorganizar me da el siguiente error:
Java.lang.NoClassDefFoundError

Aquí esta detallado:

Executing Reorganization...
CLASSPATH=gxclassr.zip;GxUtils.jar;.;C:\Documents and Settings\Administrador\Escritorio\postgresql-8.3-606.jdbc3.jar
C:\Archivos de programa\Microsoft SDK for Java 4.0\Bin\JView.exe /p Reorganization
java.lang.NoClassDefFoundError
at java/lang/Class.forName (Class.java)
at com/genexus/db/driver/GXConnection.registerDriver
at com/genexus/db/driver/GXConnection.connectJDBCDriver
at com/genexus/db/driver/GXConnection.connect
at com/genexus/db/driver/GXConnection.<init>
at com/genexus/db/driver/GXConnection.<init>
at com/genexus/db/LocalUserInformation.createConnection
at com/genexus/db/LocalUserInformation.getConnection
at com/genexus/db/LocalDBConnectionManager.getConnection
at com/genexus/db/DBConnectionManager.executeStatement
at com/genexus/ExecuteDirectSQL.execute
at gxrgza.execute_int (gxrgza.java)
at gxrgza.execute (gxrgza.java)
at Reorganization.execute (Reorganization.java)
at com/genexus/GXReorganization.executeReorg
at com/genexus/GXReorganization.executeReorg
at Reorganization.main (Reorganization.java)

1 Success - 0 Errors - 1 Canceled
Reorganization Canceled.

Por favor me podrian ayudar? Como podria solucionar este error?
Gracias desde ya y saludos