LHC@home

I installed Boinc w/out VM. I happened to already have Virtualbox installed, and Atlas is trying to use it during the day, when I'm using VMs, and causing errors when it tries to spin up a VM, but can't, because I'm also using a different brand of VM which locks Virtualbox out of operating while in use.
It would be beneficial if VM use could be limited to certain times of the day. I would like it to still be able to process non-vm tasks during the day for LHC.