What happen if you want to run more VMs than you physical memory allows ? I suppose you are using VMWARE Workstation, ok ?!?
- Go to Edit / Preferences
- on the memory tab set it to allow memory swap
![](http://3.bp.blogspot.com/_pwQNRN85CRE/S3PxNk7T3nI/AAAAAAAAAAc/NWq0mQyuyjY/s320/New+Picture+(1).jpg)
of course your performance would not be the same, but, it's a workaround.
good luck