This simple batch file launches Minecraft, but with the amount of memory specified in the batch file, not at the default 1GB amount. This helps eliminate the ?Out of Memory’ issues and other issues using high definition texture packs. It uses the concepts applied by server wrappers to manage jar files while providing a relatively smooth experience for the end user.
If this does not work for you, edit the batch file to show the appropriate location and version of Java on your computer. To adjust the amount of RAM used, Xms is the minimum amount while Xmx is the maximum amount. (1,536MB = 1.5GB Ram, 2048MB = 2GB of Ram).
1) Choose the appropriate file (the sizes in GB are amounts to give Minecraft, not what you have in your computer!)
2) Copy the batch file (.bat) to the same directory (folder) where Minecraft.exe is located.
3) Run the batch file from now on to allocate more memory.