Changing the date and time in the BIOS of a virtual machine

Question

I want to change the date in Virtual Machine, but I want to do this on the command line. I am using this line:

VBoxManage modifyvm MyVirtSystem -biossystemtimeoffset -1209600000 

It should change the date to two weeks ago, but I get this error message:

 VBoxManage.exe: error: Failed to create the VirtualBox object! VBoxManage.exe: error: Code CO_E_SERVER_EXEC_FAILURE (0x80080005) - Server execu tion failed (extended info not available) VBoxManage.exe: error: Most likely, the VirtualBox COM server is not running or failed to start. 

Do you have any ideas what I'm doing wrong?

Answer 1

There are a few things to keep in mind when working with the BIOS bias, firstly, you did not specify a double dash in your command. I tried this with one of my virtual machines, and I needed to make two dashes for this option (although I have a different error than you reported). Here is the command I used:

 VBoxManage modifyvm MyVirtSystem --biossystemtimeoffset -1209600000 

The next is to make sure that you have the appropriate permissions to modify the xml configuration file for your virtual machine. I have seen many times when VirtualBox is launched after installation with elevated (or even different users) credentials, a virtual machine is created, and then, without the same privileges, ordinary users are prohibited from changing the configuration due to file permissions.

The last thing you need to know, you may need to disable any time synchronization services, perhaps even guest extensions, to prevent guest clocks from syncing with the correct time. For a Windows guest, you would like to stop / disable VirtulBox Guest Add-ons and Windows Time Services.