I bought a new computer (HP) which comes with windows 8 64-bit. It has a A4 dualcore CPU at 2.7GHz. I just installed Minecraft and wanted to test the new snapshots, but the game kept crashing when opening worlds or creating new ones. Then, I tryed the official versions that I had previously used on my old windows 8 32-bit computer, but it crashed as well. The taks manager says that java is using 100% of the CPU. The launcher gives my this:

Client> 2013-09-20 09:29:22 [CLIENT] [INFO] Setting user: F1TZremo
Client> 2013-09-20 09:29:22 [CLIENT] [INFO] (Session ID is token:662680271f8b482699170c3beeb13bed:fea0735f28b24eef93c05e6fc20159ac)
Client> 2013-09-20 09:29:23 [CLIENT] [INFO] LWJGL Version: 2.9.0
Client> 2013-09-20 09:29:24 [CLIENT] [INFO] Reloading ResourceManager: Default
Client>
Client> Starting up SoundSystem...
Client> Initializing LWJGL OpenAL
Client> (The LWJGL binding of OpenAL. For more information, see http://www.lwjgl.org)
Client> OpenAL initialized.
Client>
Client> 2013-09-20 09:29:37 [SERVER] [INFO] Starting integrated minecraft server version 1.6.2
Client> 2013-09-20 09:29:37 [SERVER] [INFO] Generating keypair
Client> 2013-09-20 09:29:38 [SERVER] [INFO] Preparing start region for level 0
Client> 2013-09-20 09:29:39 [SERVER] [INFO] Preparing spawn area: 9%
Client> 2013-09-20 09:29:40 [SERVER] [INFO] Preparing spawn area: 30%
Client> 2013-09-20 09:29:41 [SERVER] [INFO] Preparing spawn area: 56%
Client> 2013-09-20 09:29:42 [SERVER] [INFO] Preparing spawn area: 84%
Client> loading single player
Client> 2013-09-20 09:29:43 [SERVER] [INFO] F1TZremo[/127.0.0.1:0] logged in with entity id 180 at (233.5, 64.0, 53.5)
Client> 2013-09-20 09:29:43 [SERVER] [INFO] F1TZremo joined the game
Client> Setting up custom skins
Client> 2013-09-20 09:29:49 [SERVER] [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
Game ended with bad state (exit code -805306369)

I don't know what to do, neither how to replicate it.

Edit: The CPU is a AMD A4-5150M with 2.7GHz.