Minecraft can crash due to several reasons depending on your system configurations and other technical aspects. The most common are- pre-rendered frames are enabled, a 32 bit version of Java is installed on a 64 bit machine, game affinity issue, registry configurations, and so on. Do the steps given below until your problem is fixed:
A\ Install 64 bit Java Version on your 64 Bit Windows:
1. Right click My Computer desktop icon, select Properties.
2. Check-out the version of Microsoft Windows installed. If it is a 64 bit, continue the following steps.
3. Visit official website of Java, type "check installed version" in the Search box and use their online tool to check whether or not you have a 64 bit Java version installed.
4. If the installed version is 64 bit, there is no worry. Else download and install a 64 bit version.
B] Disable Pre-Rendered Frames:
1. Double click NVIDIA Control Panel shortcut.
2. Click Manage 3D Settings | VSync.
3. Set Pre-Rendered Frames disabled. [To disable it, you have to change its value to 0]
4. Enable Triple Buffering.
5. Disable VSync
6. Save and close the settings.
C] Set Game Affinity:
1. Open Task Manager.
2. Click Processes
3. Right click Minecraft.exe.
4. Select Set Affinity option.
5. Check-up CPU 0 box and keep others unchecked.
6. Click OK.
For more information and details, please visit:
http://minecraftcrash.com/fix-minecraft-crashes/