How do I boot VMWare guest with gParted in VMWare Infrastructure Client?

If you attached the GParted ISO as shown in the image below

and it didn't boot, you may need to change the boot order in the VM BIOS. The easiest way to get to the BIOS is to go to edit settings, select the "Options" tab, then highlight "BIOS Options". Check the box under "Force BIOS setup".

Once you're in BIOS, it's just like a normal PC, edit the boot devices and make sure the CD drive has priority over the hard disk.