RHEL 7 installation doesn't start in Virtual Box

Dears,

I'm trying to install RHEL 7.1 evaluation version (iso file) on Oracle Virtualbox (4.3.28), but after selecting "Install RHEL 7.1" Virtual box screen just goes blank. Please see the attached image.
Here are some options used in Virtual box:

General:
OS: RedHat (32 bit)
System:
Base memory: 1024 MB

Storage:
Controller: IDE
IDE secondary master, [optical drive]
Sata port 0, redhat.vdi

Kindly assist me with this problem. Please let me know if you need any more info.

Thanks and Regards
Barani