"Unknown Error" occuring whenever opening Minecraft

System.getProperty('java.version') == '1.6.0_20'
----
[20:50:58 ERROR]: Game ended with bad state (exit code -805306369)

Your Java version is ancient! Please update to 1.7.0_72 or 1.8.0_25 from here: http://www.oracle.com/technetwork/java/javase/downloads/index.html. Although I'm not a moderator, I'd recommended that you update to 1.8.0_25 as Oracle will cease public updates of Java 7 in April of 2015!

If the issue still persists, then please read this regarding exit code -805306369: http://hopper.minecraft.net/help/exit-code/code-805306369/

Thank you for the heads up! I updated to the latest version of java, and all went well for a while. After a short while I got this:

[22:24:27] [Client thread/INFO]: Setting user: DESTRUCTO88
[22:24:27] [Client thread/INFO]: (Session ID is token:525fc594608d43249b87cfe5bf85a56a:6bf074334bc4429c965a90d016c4bbd3)
[22:24:32] [Client thread/INFO]: LWJGL Version: 2.9.1
[22:24:32] [Client thread/INFO]: Reloading ResourceManager: Default
[22:24:35] [Sound Library Loader/INFO]: Starting up SoundSystem...
[22:24:36] [Thread-6/INFO]: Initializing LWJGL OpenAL
[22:24:36] [Thread-6/INFO]: (The LWJGL binding of OpenAL. For more information, see http://www.lwjgl.org)
[22:24:40] [Thread-6/INFO]: OpenAL initialized.
[22:24:40] [Sound Library Loader/INFO]: Sound engine started
[22:24:47] [Client thread/INFO]: Created: 512x512 textures-atlas
[22:24:49] [Client thread/ERROR]: ########## GL ERROR ##########
[22:24:49] [Client thread/ERROR]: @ Post startup
[22:24:49] [Client thread/ERROR]: 1281: Invalid value
[22:24:50] [Client thread/ERROR]: ########## GL ERROR ##########
[22:24:50] [Client thread/ERROR]: @ Pre render
[22:24:50] [Client thread/ERROR]: 1281: Invalid value
[22:24:59] [Server thread/INFO]: Starting integrated minecraft server version 1.8.1
[22:24:59] [Server thread/INFO]: Generating keypair
[22:25:00] [Server thread/INFO]: Preparing start region for level 0
[22:25:01] [Server thread/INFO]: Preparing spawn area: 12%
[22:25:02] [Server thread/INFO]: Preparing spawn area: 55%
[22:25:03] [Server thread/INFO]: Preparing spawn area: 93%
Jan 4, 2015 10:25:03 PM io.netty.util.internal.PlatformDependent <clinit>
INFO: Your platform does not provide complete low-level API for accessing direct buffers reliably. Unless explicitly requested, heap buffer will always be preferred to avoid potential system unstability.
[22:25:04] [Server thread/INFO]: Changing view distance to 4, from 10
[22:25:05] [Server thread/INFO]: DESTRUCTO88[local:E:24d68fc0] logged in with entity id 397 at (-200.32576150766707, 70.0, -223.50488449198144)
[22:25:05] [Server thread/INFO]: DESTRUCTO88 joined the game
[22:25:07] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 2999ms behind, skipping 59 tick(s)
[22:25:41] [Server thread/INFO]: Saving and pausing game...
[22:25:41] [Server thread/INFO]: Saving chunks for level 'PURGATORIUM'/Overworld
[22:25:41] [Server thread/INFO]: Saving chunks for level 'PURGATORIUM'/Nether
[22:25:41] [Server thread/INFO]: Saving chunks for level 'PURGATORIUM'/The End
[22:25:46] [Server thread/INFO]: Saving and pausing game...
[22:25:46] [Server thread/INFO]: Saving chunks for level 'PURGATORIUM'/Overworld
[22:25:47] [Server thread/INFO]: Saving chunks for level 'PURGATORIUM'/Nether
[22:25:47] [Server thread/INFO]: Saving chunks for level 'PURGATORIUM'/The End

Is my laptop just too slow to play Minecraft anymore?

All other bug reports say that its a tech support issue, so I'd recommend the Mojang Support Center: https://help.mojang.com

This is a technical support issue, please follow the instructions of this guide: Exit Code: -805306369. If all that won't help, please use the Mojang Support Center.

Wow, I have only Windows XP and I can't upgrade to Java 8 or higher. WOW.