Hey, i bought minecraft 3 years ago and didnt played it last year, now i downloaded it again but i cant start it. when i klick start i get this message:
---- Minecraft Crash Report ----
// My bad.

Time: 21.01.15 17:20
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 7 (amd64) version 6.1
Java Version: 1.8.0_25, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 69153288 bytes (65 MB) / 167870464 bytes (160 MB) up to 1060372480 bytes (1011 MB)
JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
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: 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)

I realy hope someone can help me :/
thanks
crazzyminer :)