I am using the microsoft supplied vhd files to test ie6. However, in the VM, browsing to localhost does not hit the webserver running on localhost of the host machine (Windows 7). Is there an easy way to hit the webserver on the host machine in the VM?
"localhost" on your virtual machine is just that, the hostname corresponding to the loopback address of the virtual machine. Try accessing the site with the IP address of the host machine it's running under. To find out what that is, open a command window in the host machine and then use the IP address you get when you use the command "ipconfig".
If at all possible, try to configure your host machine with a static IP address so you don't have to find out the host IP all the time. You may also want to add an entry to your hosts file to make it so you don't have to type in an address every time.