Minecraft Launcher no inicia

Hola a todos, con Windows 7 el Minecraft me iba perfecto, pero con Windows 8.1, tengo un error y no me funciona. Al abrir el launcher y darle a Conectar, se carga y al final me da un error:

---- Minecraft Crash Report ----// Quite honestly, I wouldn’t worry myself about that.

Time: 15/12/14 12:17
Description: Initializing game

org.lwjgl.LWJGLException: Pixel format not accelerated
at org.lwjgl.opengl.WindowsPeerInfo.nChoosePixelFormat(Native Method)
at org.lwjgl.opengl.WindowsPeerInfo.choosePixelFormat(WindowsPeerInfo.java:52)
at org.lwjgl.opengl.WindowsDisplay.createWindow(WindowsDisplay.java:252)
at org.lwjgl.opengl.Display.createWindow(Display.java:306)
at org.lwjgl.opengl.Display.create(Display.java:848)
at org.lwjgl.opengl.Display.create(Display.java:757)
at org.lwjgl.opengl.Display.create(Display.java:739)
at bss.an(SourceFile:526)
at bss.ak(SourceFile:355)
at bss.a(SourceFile:302)
at net.minecraft.client.main.Main.main(SourceFile:124)

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

– Head –
Stacktrace:
at org.lwjgl.opengl.WindowsPeerInfo.nChoosePixelFormat(Native Method)
at org.lwjgl.opengl.WindowsPeerInfo.choosePixelFormat(WindowsPeerInfo.java:52)
at org.lwjgl.opengl.WindowsDisplay.createWindow(WindowsDisplay.java:252)
at org.lwjgl.opengl.Display.createWindow(Display.java:306)
at org.lwjgl.opengl.Display.create(Display.java:848)
at org.lwjgl.opengl.Display.create(Display.java:757)
at org.lwjgl.opengl.Display.create(Display.java:739)
at bss.an(SourceFile:526)
at bss.ak(SourceFile:355)

– Initialization –
Details:
Stacktrace:
at bss.a(SourceFile:302)
at net.minecraft.client.main.Main.main(SourceFile:124)

– System Details –
Details:
Minecraft Version: 1.8.1
Operating System: Windows 8.1 (x86) version 6.3
Java Version: 1.8.0_25, Oracle Corporation
Java VM Version: Java HotSpot™ Client VM (mixed mode), Oracle Corporation
Memory: 26118192 bytes (24 MB) / 83558400 bytes (79 MB) up to 518979584 bytes (494 MB)
JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
Launched Version: 1.8.1
LWJGL: 2.9.1
OpenGL: ERROR RuntimeException: No OpenGL context found in the current thread.
GL Caps:
Using VBOs: No
Is Modded: Very likely; Jar signature invalidated
Type: Client (map_client.txt)
Resource Packs:
Current Language: ERROR NullPointerException: null
Profiler Position: N/A (disabled)

¿Por qué puede ser?