**NOTE** Be sure you are running 64bit version of Java if you have a 64 bit OS.
- Open your CONTROL PANEL.
- Type 'Java' inside the 'Search Control Panel' box.
- Click the Java icon that pops up.
- Click the Java tab.
- Click View...
- Make sure there is only ONE line in here; any more lines could cause issues.
If you have multiple lines uninstall all versions of Java from your system and download Java JDK 7 from the following link.
Make sure to get the x64 version if you have a 64-bit OS.
http://java.com/en/download/manual.jsp - Change the memory runtime parameter ("-Xmx").
For instance, you may need to set it to:
-Xincgc -Xmx2048M
Change the value between "-Xmx" and "M" depending on how much RAM you have.
For 32-bit Operating Systems, 768M may work well. If you have 64-bit, or that doesn't work, try other values, such as:
1G
1536M
2G
The best value for you varies depending on how much System RAM you have. Be careful not to give it more than 500 MB or so from your physical amount! - Click OK.
- Run Minecraft