Not able to move from RHEL6 64 bit to RHEL5 32 bit

Hi,

I have a virtual machine created on RHEL 6 64 bit OS on Esxi 4.1

I want to install a RHEL 5 32 bit on this virutal machine. For that I changed the Guest OS to be RHEL 5 32 bit from the settings and supplied a rhel 5 32 bit iso in the CDROM. also I changed the boot order to boot from CD first.

However, it doesn't change the guest OS to RHEL5,  doesn't detect CD containing RHEL5 and proceeds to boot from harddisk with RHEL 6 64 bit.

Please suggest if this is a possible change for an exisiting virtual machine or I need to delete the machine and recreate with RHEL 5 32 bit?

Thanks,

Manisha