Error : INstaller has run out of Heap space, please try installer with increase Heap space

Hi,
I am trying to set-up jboss-eap-6.4.0-installer.jar (Patch: jboss-eap-6.4.7-patch) & jboss-bpmsuite-6.3.0.GA-installer.jar & getting error.
I am using this configuration (-Xms512m -Xmx1024m ) and i am unable to increase beyond -1024. My system has a limitation and i was unable to increase memory beyond 1024m.

I am using Windows-7 and jdk1.8.0_45
Please suggest on how to overcome this.

Thanks,
Malli