I try installing it vanilla and it doesent work still i get this error
2012-10-26 18:32:59 [iNFO] [ForgeModLoader] Forge Mod Loader version 4.2.4.420 for Minecraft 1.4.2 loading
2012-10-26 18:32:59 [FINEST] [ForgeModLoader] All core mods are successfully located
2012-10-26 18:32:59 [FINEST] [ForgeModLoader] Discovering coremods
2012-10-26 18:32:59 [FINEST] [ForgeModLoader] Found a candidate coremod CodeChickenCore 0.6.0.jar
2012-10-26 18:32:59 [FINEST] [ForgeModLoader] Loading coremod CodeChickenCore 0.6.0.jar
2012-10-26 18:32:59 [FINEST] [ForgeModLoader] Loaded coremod CodeChickenCore 0.6.0.jar
2012-10-26 18:32:59 [FINEST] [ForgeModLoader] Found a candidate coremod NotEnoughItems 1.4.0.0.jar
2012-10-26 18:32:59 [FINEST] [ForgeModLoader] Loading coremod NotEnoughItems 1.4.0.0.jar
2012-10-26 18:32:59 [FINEST] [ForgeModLoader] Loaded coremod NotEnoughItems 1.4.0.0.jar
2012-10-26 18:32:59 [FINEST] [ForgeModLoader] Found library file argo-2.25.jar present and correct in lib dir
2012-10-26 18:32:59 [FINEST] [ForgeModLoader] Found library file guava-12.0.1.jar present and correct in lib dir
2012-10-26 18:32:59 [FINEST] [ForgeModLoader] Found library file asm-all-4.0.jar present and correct in lib dir
2012-10-26 18:33:00 [FINEST] [ForgeModLoader] Running coremod plugins
2012-10-26 18:33:00 [FINEST] [ForgeModLoader] Running coremod plugin FMLCorePlugin
2012-10-26 18:33:04 [iNFO] [sTDERR] Exception in thread "Thread-5" java.lang.RuntimeException: java.lang.RuntimeException: java.lang.ClassNotFoundException: cpw.mods.fml.common.asm.FMLSanityChecker
2012-10-26 18:33:04 [iNFO] [sTDERR] at cpw.mods.fml.relauncher.FMLRelauncher.setupHome(FMLRelauncher.java:175)
2012-10-26 18:33:04 [iNFO] [sTDERR] at cpw.mods.fml.relauncher.FMLRelauncher.relaunchApplet(FMLRelauncher.java:242)
2012-10-26 18:33:04 [iNFO] [sTDERR] at cpw.mods.fml.relauncher.FMLRelauncher.appletEntry(FMLRelauncher.java:212)
2012-10-26 18:33:04 [iNFO] [sTDERR] at net.minecraft.client.MinecraftApplet.init(MinecraftApplet.java:28)
2012-10-26 18:33:04 [iNFO] [sTDERR] at net.minecraft.Launcher.replace(Launcher.java:136)
2012-10-26 18:33:04 [iNFO] [sTDERR] at net.minecraft.Launcher$1.run(Launcher.java:79)
2012-10-26 18:33:04 [iNFO] [sTDERR] Caused by: java.lang.RuntimeException: java.lang.ClassNotFoundException: cpw.mods.fml.common.asm.FMLSanityChecker
2012-10-26 18:33:04 [iNFO] [sTDERR] at cpw.mods.fml.relauncher.RelaunchLibraryManager.handleLaunch(RelaunchLibraryManager.java:264)
2012-10-26 18:33:04 [iNFO] [sTDERR] at cpw.mods.fml.relauncher.FMLRelauncher.setupHome(FMLRelauncher.java:155)
2012-10-26 18:33:04 [iNFO] [sTDERR] ... 5 more
2012-10-26 18:33:04 [iNFO] [sTDERR] Caused by: java.lang.ClassNotFoundException: cpw.mods.fml.common.asm.FMLSanityChecker
2012-10-26 18:33:04 [iNFO] [sTDERR] at cpw.mods.fml.relauncher.RelaunchClassLoader.findClass(RelaunchClassLoader.java:126)
2012-10-26 18:33:04 [iNFO] [sTDERR] at java.lang.ClassLoader.loadClass(Unknown Source)
2012-10-26 18:33:04 [iNFO] [sTDERR] at java.lang.ClassLoader.loadClass(Unknown Source)
2012-10-26 18:33:04 [iNFO] [sTDERR] at java.lang.Class.forName0(Native Method)
2012-10-26 18:33:04 [iNFO] [sTDERR] at java.lang.Class.forName(Unknown Source)
2012-10-26 18:33:04 [iNFO] [sTDERR] at cpw.mods.fml.relauncher.RelaunchLibraryManager.handleLaunch(RelaunchLibraryManager.java:256)
2012-10-26 18:33:04 [iNFO] [sTDERR] ... 6 more
2012-10-26 18:33:04 [iNFO] [sTDERR] Caused by: java.lang.ClassCircularityError: codechicken/core/asm/ObfuscationManager$ClassMapping
2012-10-26 18:33:04 [iNFO] [sTDERR] at codechicken.nei.asm.NEITransformer.transformer001(NEITransformer.java:31)
2012-10-26 18:33:04 [iNFO] [sTDERR] at codechicken.nei.asm.NEITransformer.transform(NEITransformer.java:102)
2012-10-26 18:33:04 [iNFO] [sTDERR] at cpw.mods.fml.relauncher.RelaunchClassLoader.runTransformers(RelaunchClassLoader.java:163)
2012-10-26 18:33:04 [iNFO] [sTDERR] at cpw.mods.fml.relauncher.RelaunchClassLoader.findClass(RelaunchClassLoader.java:119)
2012-10-26 18:33:04 [iNFO] [sTDERR] ... 11 more