Any advice?

My Minecraft won't start up; it keeps showing the Mojang logo page, then crashes. Before I force updated it, it went smoothly, though.
Here's a run-through of the crash report:
~~~
---- Minecraft Crash Report ----
// Don't be sad. I'll do better next time, I promise!

Time: 2/23/13 9:22 PM
Description: Failed to start game

java.lang.NullPointerException
at java.io.Reader.<init>(Unknown Source)
at java.io.InputStreamReader.<init>(Unknown Source)
at bn.a(SourceFile:56)
at bn.a(SourceFile:91)
at net.minecraft.client.Minecraft.a(SourceFile:249)
at asq.a(SourceFile:56)
at net.minecraft.client.Minecraft.run(SourceFile:515)
at java.lang.Thread.run(Unknown Source)


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

-- System Details --
Details:
Minecraft Version: 1.4.7
Operating System: Windows 7 (x86) version 6.1
Java Version: 1.7.0_15, Oracle Corporation
Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
Memory: 925925776 bytes (883 MB) / 1037959168 bytes (989 MB) up to 1037959168 bytes (989 MB)
JVM Flags: 2 total; -Xms1024m -Xmx1024m
AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
Suspicious classes: IWrUpdater, Config, WrUpdates, ...]
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
ModLoader: Mods loaded: 1
ModLoader 1.4.7

LWJGL: 2.4.2
OpenGL: AMD Radeon(TM) HD 6520G GL version 4.1.11247 Compatibility Profile Context, ATI Technologies Inc.
Is Modded: Very likely; Jar signature invalidated
Type: Client (map_client.txt)
Texture Pack: Faithful v.RG331.zip
Profiler Position: N/A (disabled)
Vec3 Pool Size: ~~ERROR~~ NullPointerException: null
~~~
Any advice on how to fix it?