I have tried this on both VMware Player and VirtuaBox. I am working on Windows 7. In the hypervisor I install a standard Ubuntu 10.04 image. I wish to set up a web server on this image for incoming connections from my LAN. So I chose bridged network connection. I am trying to ping the VM from my host machine but I don't get any reply. What might be the problem. I am fine with a solution on either of the hypervisors.
My first thought is your Win7 box's firewall is on.
Edit* read it wrong, thought you said from another machine. If you are on the host machine the firewall shouldn't be an issue, though you can try it to be sure.
There could also be a firewall, or a configuration on the Ubuntu box by default that causes it to drop ICMP packets.
Or the bridging didnt take and its still using NAT maybe? What is the actual IP that the Ubuntu machine has? Is it one on your LAN or is it a NAT'd one behind the Virtual router?
cli command ifconfig