Frezes as soon as I join a server.

Please attach the output of the development console.

Incomplete.

Well it freezes the whole computer so the only way i can get back to the home screen of my computer, is to turn it off and restart. Sometimes when i can bring it back without restarting the computer, i cant do anything with the minecraft launcher, thats frozen as well, but i can do other things with the computer.

Once when I re-downloadedMinecraft with my brothers account it did work but, that doesnt work anymore...

Please force a crash by pressing F3 + C for 10 seconds while ingame (and not frozen) and attach the crash report here.

---- Minecraft Crash Report ----
// Daisy, daisy...

Time: 7/13/13 9:15 PM
Description: Manually triggered debug crash

java.lang.Throwable
	at ats.k(SourceFile:1238)
	at ats.S(SourceFile:663)
	at ats.d(SourceFile:619)
	at net.minecraft.client.main.Main.main(SourceFile:101)


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

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [bdf['WolfBaby07'/84149, l='MpServer', x=-1425.64, y=70.62, z=1610.18]]
	Chunk stats: MultiplayerChunkCache: 441
	Level seed: 0
	Level generator: ID 02 - largeBiomes, ver 0. Features enabled: false
	Level generator options: 
	Level spawn location: World: (-372,68,151), Chunk: (at 12,4,7 in -24,9; contains blocks -384,0,144 to -369,255,159), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
	Level time: 26439735 game time, 19864041 day time
	Level dimension: 0
	Level storage version: 0x00000 - Unknown?
	Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false)
	Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: false
	Forced entities: 32 total; [bdf['WolfBaby07'/84149, l='MpServer', x=-1425.64, y=70.62, z=1610.18], tq['Skeleton'/84305, l='MpServer', x=-1430.50, y=67.00, z=1573.50], tq['Skeleton'/84245, l='MpServer', x=-1399.50, y=69.00, z=1572.50], tv['Zombie'/84310, l='MpServer', x=-1382.56, y=24.00, z=1655.69], tv['Zombie'/84243, l='MpServer', x=-1397.22, y=69.00, z=1571.09], tf['Enderman'/84309, l='MpServer', x=-1442.75, y=66.00, z=1637.69], tv['Zombie'/84230, l='MpServer', x=-1431.50, y=64.00, z=1643.50], tq['Skeleton'/84187, l='MpServer', x=-1402.50, y=26.00, z=1615.50], te['Creeper'/84228, l='MpServer', x=-1387.50, y=42.00, z=1602.50], rx['Pig'/84294, l='MpServer', x=-1426.25, y=64.00, z=1652.75], rx['Pig'/84293, l='MpServer', x=-1427.69, y=64.00, z=1651.31], tv['Zombie'/84225, l='MpServer', x=-1396.50, y=64.00, z=1624.50], rp['Chicken'/84292, l='MpServer', x=-1429.50, y=64.00, z=1649.50], tv['Zombie'/84237, l='MpServer', x=-1429.50, y=30.00, z=1614.50], tv['Zombie'/84236, l='MpServer', x=-1427.50, y=30.00, z=1619.50], te['Creeper'/84235, l='MpServer', x=-1421.50, y=30.00, z=1621.50], te['Creeper'/84234, l='MpServer', x=-1422.50, y=30.00, z=1619.50], tf['Enderman'/84233, l='MpServer', x=-1429.63, y=64.00, z=1647.44], tq['Skeleton'/84277, l='MpServer', x=-1393.50, y=14.00, z=1596.50], tv['Zombie'/84281, l='MpServer', x=-1454.50, y=49.00, z=1597.50], st['entity.MinecartChest.name'/84159, l='MpServer', x=-1386.50, y=19.50, z=1551.50], tf['Enderman'/84261, l='MpServer', x=-1445.50, y=67.00, z=1647.50], st['entity.MinecartChest.name'/84158, l='MpServer', x=-1385.50, y=20.50, z=1565.50], st['entity.MinecartChest.name'/84157, l='MpServer', x=-1412.50, y=24.50, z=1674.50], tf['Enderman'/84263, l='MpServer', x=-1447.50, y=67.00, z=1644.50], st['entity.MinecartChest.name'/84155, l='MpServer', x=-1397.50, y=23.34, z=1656.50], st['entity.MinecartChest.name'/84154, l='MpServer', x=-1382.50, y=15.50, z=1583.50], st['entity.MinecartChest.name'/84152, l='MpServer', x=-1409.50, y=27.50, z=1643.50], st['entity.MinecartChest.name'/84151, l='MpServer', x=-1400.50, y=23.50, z=1621.50], oc['entity.ItemFrame.name'/84150, l='MpServer', x=-1425.50, y=70.50, z=1615.94], te['Creeper'/84265, l='MpServer', x=-1435.50, y=46.00, z=1584.50], te['Creeper'/84266, l='MpServer', x=-1396.50, y=19.00, z=1571.50]]
	Retry entities: 0 total; []
	Server brand: craftbukkit
	Server type: Non-integrated multiplayer server
Stacktrace:
	at bda.a(SourceFile:284)
	at ats.b(SourceFile:1761)
	at ats.d(SourceFile:628)
	at net.minecraft.client.main.Main.main(SourceFile:101)

-- System Details --
Details:
	Minecraft Version: 1.6.2
	Operating System: Windows 7 (x86) version 6.1
	Java Version: 1.6.0_26, Sun Microsystems Inc.
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Sun Microsystems Inc.
	Memory: 71878872 bytes (68 MB) / 151629824 bytes (144 MB) up to 518979584 bytes (494 MB)
	JVM Flags: 1 total; -Xmx512M
	AABB Pool Size: 21762 (1218672 bytes; 1 MB) allocated, 2 (112 bytes; 0 MB) used
	Suspicious classes: No suspicious classes found.
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Launched Version: 1.6.2
	LWJGL: 2.9.0
	OpenGL: ATI Radeon HD 3450 - Dell Optiplex GL version 2.1.8870, ATI Technologies Inc.
	Is Modded: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)
	Resource Pack: Default
	Current Language: English (UK)
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 1350 (75600 bytes; 0 MB) allocated, 24 (1344 bytes; 0 MB) used

Can you reproduce this when joining a vanilla server? It looks like you are using a bukkit one.
Also, your Java version is out of date. Please update your Java to the latest version (1.7.0_25): http://www.java.com/en/download/. Keep in mind that when using a 32-bit browser on a 64-bit OS the automatic version detection will only show the 32-bit version of Java, the 64-bit version needs to be downloaded manually: http://www.java.com/en/download/manual.jsp.
Please report if the issue persists with the latest Java version.

After updating Java it will crash: MC-20163