What is the purpose of the ISO?

Hi

I did a conversion of a vm workstation vm to an OVF using ovftool (yuck, coammndline!!)

At the end of this my Win7 x 86 vm had an ISO in it as well as the .ovf and .vmdk

When i open the ISO it is a Windows 8 Preview ISO !! used on another VM

So...

>> What is the purpose of the ISO ?

>> Why would the utility have done this ?

(nb:

the vms has an exntry like

ide1:0.present = "TRUE"
ide1:0.fileName = "D:\Downloads\Windows8-ConsumerPreview-64bit-English.iso"
ide1:0.deviceType = "cdrom-image"

which i assume is the CD drive mapping from previously)

>> Is this a known trap, i..e. you should ensure no CD is mapped when you shutdown a VM ?

Thanks!