If you need to prevent date and time synchronization between a Virtual PC 2007 virtual machine and its host machine, look at this post for the necessary steps but if you need to achieve the same result with a Windows Virtual PC virtual machine, you can do so by adding the following line to the vmc file for your virtual machine:
You can achieve the above by also running the following visual basic script:
'Title: Script to disable timesync for a VM.
'Usage: cscript ScriptName <vmname>
Set objVPC = CreateObject("VirtualPC.Application")
'Get virtual machine name from command-line parameter
Set objVM = objVPC.FindVirtualMachine(WScript.Arguments(0))
'Disable TimeSync During Boot Time
errReturn = objVM.SetConfigurationValue("hardware/bios/time_sync_at_boot", false)
'Get object for GuestOS
Set objGuestOS = objVM.GuestOS
'Disable TimeSync During VM Execution
objGuestOS.IsHostTimeSyncEnabled = false
Copy the above in a file with the vbs extension and run it from a command-line prompt with the following instruction:
cscript x:\path\MyScript.vbs "MyVirtualMachineName"
where MyScript.vbs is the name of your script file, x:\path is the file full path and MyVirtualMachineName is the name of your WMV virtual machine.