When i launch minecraft it crashed and says this?

---- Minecraft Crash Report ----
// Why is it breaking.

Time: 25/01/14 10:20
Description: Initializing game

org.lwjgl.LWJGLException: Pixel format not accelerated
at org.lwjgl.opengl.WindowsPeerInfo.nChoose… Method)
at org.lwjgl.opengl.WindowsPeerInfo.chooseP…
at org.lwjgl.opengl.WindowsDisplay.createWi…
at org.lwjgl.opengl.Display.createWindow(Di…
at org.lwjgl.opengl.Display.create(Display…
at org.lwjgl.opengl.Display.create(Display…
at org.lwjgl.opengl.Display.create(Display…
at azi.ad(SourceFile:325)
at azi.f(SourceFile:696)
at net.minecraft.client.main.Main.main(Sour…

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

-- Head --
Stacktrace:
at org.lwjgl.opengl.WindowsPeerInfo.nChoose… Method)
at org.lwjgl.opengl.WindowsPeerInfo.chooseP…
at org.lwjgl.opengl.WindowsDisplay.createWi…
at org.lwjgl.opengl.Display.createWindow(Di…
at org.lwjgl.opengl.Display.create(Display…
at org.lwjgl.opengl.Display.create(Display…
at org.lwjgl.opengl.Display.create(Display…
at azi.ad(SourceFile:325)

-- Initialization --
Details:
Stacktrace:
at azi.f(SourceFile:696)
at net.minecraft.client.main.Main.main(Sour…

-- System Details --
Details:
Minecraft Version: 1.7.4
Operating System: Windows 7 (x86) version 6.1
Java Version: 1.7.0_51, Oracle Corporation
Java VM Version: Java HotSpot(TM) Client VM (mixed mode, sharing), Oracle Corporation
Memory: 5068232 bytes (4 MB) / 26808320 bytes (25 MB) up to 518979584 bytes (494 MB)
JVM Flags: 2 total; -XX: HeapDumpPath=MojangTricksIntelDriver… -Xmx512M
AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
Launched Version: 1.7.4
LWJGL: 2.9.1
OpenGL: ~~ERROR~~ RuntimeException: No OpenGL context found in the current thread.
GL Caps:
Is Modded: Probably not. Jar signature remains and client brand is untouched.
Type: Client (map_client.txt)
Resource Packs: []
Current Language: ~~ERROR~~ NullPointerException: null
Profiler Position: N/A (disabled)
Vec3 Pool Size: ~~ERROR~~ NullPointerException: null
Anisotropic Filtering: Off (1)