virtualbox.org

How can I set a permanent date in windows 7 every time I start windows 7.
So I want every time I start my windows 7 VM the date is on 10-10-2014.

Basically, AFAIK, you can't, at least not unless you're willing to also freeze the date/time on the host.

VirtualBox doesn't store the date and time for a VM, it reads it from the host on startup. Of course if the guest OS has internet access then it can also access a network time server and correct it's own date/time that way.

You can offset the guest date/time from the host date/time, but you would have to change the offset every time you restart the VM.

And it's all probably for naught anyway: a few simple tests can allow software to detect that time seems to be standing still (or going backwards) - and if I was supplying a time limited demo you can be sure I would implement such checks. Even if that wasn't true, you might quickly find the loss of reliable date/time file stamps quite a burden - perhaps even leading to software crashes (depends on the app).