Modding problem

So, i wanted to try make a mod. I started watching a tutorial how to start etc... On step where i don't really know how to call it somethings went wrong. Step was go to your mod directory, copy it, go to CMD, write "cd <your directory>" and then write "gradlew setupdecompworkspace". And here whole process failed because of error(?)...

FAILURE: Build failed with an exception.* What went wrong:Unable to start the daemon process.This problem might be caused by incorrect configuration of the daemon.For example, an unrecognized jvm option is used.Please refer to the user guide chapter on the daemon at https://docs.gradle.org/2.14/userguide/gradle_daemon.htmlPlease read the following process output to find out more:-----------------------Error occurred during initialization of VMCould not reserve enough space for 3145728KB object heap* Try:Run with --stacktrace option to get the stack trace. Run with --info or --debugoption to get more log output.

Someone can help with it? I use eclipse on win 7 64bit if that info is needed.