The scree to start is:

-- System Info
----------------------------------------------------------------
  Product Version       = NetBeans IDE Version 3.3 (Build 200112102331)
  IDE Versioning        = IDE/1 spec=1.43.1.1 impl=200112102331
  Operating System      = OS/2 version 20.45 running on x86
  Java; VM; Vendor      = 1.3.0; Classic VM 1.3.0; IBM Corporation
  Java Home             = E:\Java13\jre
  System Locale         = it_IT_EURO
  JIT                   = jitc
  Home Dir; Current Dir = E:\JAVA13\JRE; E:\temp\netbeans\bin
  IDE Install; User Dir = e:\temp\netbeans; e:\temp\netbeans\home
  CLASSPATH             =
e:\temp\netbeans\lib\patches\openide-compat.jar;e:\temp\netbeans\lib\core.jar;e:\temp\netbeans\lib\openide.jar;e:\temp\netbeans\lib\up
dater.jar;e:\temp\netbeans\lib\ext\crimson.jar;e:\temp\netbeans\lib\ext\jh.jar;e:\temp\netbeans\lib\ext\regexp.jar;e:\temp\netbeans\lib\ext\rmi-ext.jar;e:\temp\
netbeans\lib\ext\terminalemulator.jar;e:\temp\netbeans\lib\ext\xerces.jar;E:\Java13\lib\tools.jar;
-------------------------------------------------------------------------------
javax.xml.parsers.FactoryConfigurationError:
org.netbeans.core.xml.NbSAXParserFactoryImpl
  at
javax.xml.parsers.SAXParserFactory.newInstance(SAXParserFactory.java:157)
        at org.openide.xml.XMLUtil.createXMLReader(XMLUtil.java:69)
        at org.openide.xml.XMLUtil.createXMLReader(XMLUtil.java:43)
        at
org.openide.loaders.XMLDataObject.<clinit>(XMLDataObject.java:935)
        at org.netbeans.core.NbTheme.parseTheme(NbTheme.java:110)
        at org.netbeans.core.NbTheme.<init>(NbTheme.java:90)
        at org.netbeans.core.Main.run(Main.java:117)
        at
org.openide.TopManager.initializeTopManager(TopManager.java:120)
        at org.openide.TopManager.getDefault(TopManager.java:81)
        at org.netbeans.core.Main.main(Main.java:324)
        at org.netbeans.core.TopThreadGroup.run(TopThreadGroup.java:87)
        at java.lang.Thread.run(Thread.java:498)

this is very likely caused by jar files you have in <jdk>\jre\lib\ext.
 Try to move them to another place.  NetBeans includes a few third
party jar libraries (see <ide>\lib\ext).  If conflicting jars are
present in <jdk>\jre\lib\ext then they are used by the JVM instead of
those in <ide>\lib\ext.  We are looking for ways to make jars in
latter place to have higher precedence.  This should be solved in the
next release.

For more infos see issue #11020. For now, you can delete the
conflicting jars from {jdkhome}/jre/lib/ext.

x

*** This issue has been marked as a duplicate of 17358 ***

Resolved for 3.4.x or earlier, no new info since then -> verified.

Resolved for 3.4.x or earlier, no new info since then -> closing.