The following were the steps I followed:

 

1.  Ran the Minecraft launcher. 

2.  Created a profile that used 1.6.4

3.  Ran 1.6.4 for the first time

4.  Downloaded Forge 9.11.1 (for 1.6.4) Installer

5.  Ran the JAR file. 

6.  Did not change any of the settings in the installer window.

7.  Ran the Minecraft Launcher. 

8.  Changed the version used to release 1.6.4-Forge9.11.1.953

9.  Clicked Play.

10.  The mojang screen appeared.

11.  Then this error report:

 

--- Minecraft Crash Report ----
// I let you down. Sorry 

Time: 2/2/14 12:36 AM
Description: Initializing game

java.lang.NoClassDefFoundError: nm
at mod_ReiMinimap.getVersion(mod_ReiMinimap.java:15)
at cpw.mods.fml.common.modloader.ModLoaderModContainer.getVersion(ModLoaderModContainer.java:418)
at cpw.mods.fml.common.Loader.loadMods(Loader.java:515)
at cpw.mods.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:183)
at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:473)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:808)
at net.minecraft.client.main.Main.main(SourceFile:101)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at net.minecraft.launchwrapper.Launch.launch(Launch.java:131)
at net.minecraft.launchwrapper.Launch.main(Launch.java:27)
Caused by: java.lang.ClassNotFoundException: nm
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:186)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 13 more
Caused by: java.lang.NullPointerException
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:178)
... 15 more


A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

-- Head --
Stacktrace:
at mod_ReiMinimap.getVersion(mod_ReiMinimap.java:15)
at cpw.mods.fml.common.modloader.ModLoaderModContainer.getVersion(ModLoaderModContainer.java:418)
at cpw.mods.fml.common.Loader.loadMods(Loader.java:515)
at cpw.mods.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:183)
at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:473)

-- Initialization --
Details:
Stacktrace:
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:808)
at net.minecraft.client.main.Main.main(SourceFile:101)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at net.minecraft.launchwrapper.Launch.launch(Launch.java:131)
at net.minecraft.launchwrapper.Launch.main(Launch.java:27)

-- System Details --
Details:
Minecraft Version: 1.6.4
Operating System: Windows 8 (amd64) version 6.2
Java Version: 1.7.0_51, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 128530880 bytes (122 MB) / 475529216 bytes (453 MB) up to 954728448 bytes (910 MB)
JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
Suspicious classes: FML and Forge are installed
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
FML: ~~ERROR~~ NoClassDefFoundError: nm
Launched Version: 1.6.4-Forge9.11.1.953
LWJGL: 2.9.0
OpenGL: GeForce GTX 770M/PCIe/SSE2 GL version 4.4.0, NVIDIA Corporation
Is Modded: Definitely; Client brand changed to 'fml,forge'
Type: Client (map_client.txt)
Resource Pack: Default
Current Language: English (US)
Profiler Position: N/A (disabled)
Vec3 Pool Size: ~~ERROR~~ NullPointerException: null

 

How am I possibly going to be able to add mods if I can't even get the base program to run properly with just forge installed?

 

Any help please?

 

Disregard... I'm guessing some flaky config files creeped into my minecraft folder either during version 1.6.2 or later.  A clean install of a new MC folder cleared the issue.