Java Could not reserve enough space for object heap error

Question

I have Java7 running on 32-bit Windows and 4 GB RAM, but:

java -Xmx4G -Xms4G -jar Minecraft.jar 
java -Xmx3G -Xms3G -jar Minecraft.jar 
java -Xmx2G -Xms2G -j         


        

Answer 1

to make sure it runs the 64 bit version of java have it like this:

"c:\Program Files\Java\jre7\bin\java.exe" -Xmx1536M -Xms1536M -XX:MaxPermSize=256M -jar forge-1.6.4-9.11.1.965-universal.jar

take a look at what jre version you have installed just in case.. x64 should be in program files while x32 resides in Program Files (x86)