Windows 7 change system date (virtual machine)

I’m trying to change the system date back to 2009 in my Windows 7 Virtual Machine (I’m on a Mac).
I click the adjust date/time and change it back and it works, for about 5 seconds then returns to the current date and time.
I have turned off the sync online check box as well.
How do I get it to stay back in 2009 (while I install some software at least).
Thanks!
Answer #1
Update it in the bios. Not sure if parallels allows you to do that, but if so just but into the bios when starting the machine and change the time there. Hopefully it will stick to Windows as well.