Вот что пишет:
Bad video card drivers!
---
Minecraft was unable to start because it failed to find an accelerated OpenGL mode.
This can usually be fixed by updating the video card drivers.
--- BEGIN ERROR REPORT 7fe0271 ---
Generated 04.06.13 14:41
-- System Details --
Details:
Minecraft Version: 1.5.1
Operating System: Windows XP (x86) version 5.1
Java Version: 1.7.0_21, Oracle Corporation
Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
Memory: 453233840 bytes (432 MB) / 518979584 bytes (494 MB) up to 1037959168 bytes (989 MB)
JVM Flags: 2 total; -Xms512m -Xmx1024m
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:
LWJGL: 2.9.0
OpenGL: ~~ERROR~~ RuntimeException: No OpenGL context found in the current thread.
Is Modded: Definitely; Client brand changed to 'fml, forge'
Type: Client (map_client.txt)
Texture Pack: По умолчанию
Profiler Position: N/A (disabled)
Vec3 Pool Size: ~~ERROR~~ NullPointerException: null[failed to get system properties (java.lang.RuntimeException: No OpenGL context found in the current thread.)]
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:241)
at org.lwjgl.opengl.Display.createWindow(Display.java:311)
at org.lwjgl.opengl.Display.create(Display.java:854)
at org.lwjgl.opengl.Display.create(Display.java:763)
at org.lwjgl.opengl.Display.create(Display.java:745)
at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:394)
at net.minecraft.client.MinecraftAppletImpl.func_71384_a(SourceFile:56)
at net.minecraft.client.Minecraft.run(Minecraft.java:729)
at java.lang.Thread.run(Unknown Source)
--- END ERROR REPORT 3999c680
Обнови драйвера, а если никак-то лучше новый компьютер купи
