Error with Everest Home Edition Signed Driver

I need to fix this error with Everest Home Edition. It is saying that the driver is not digitally signed. I am using Windows Vista Business Edition 64-Bit on my HP 6715B computer. Doesn’t Windows Vista accept non-digitally signed drivers? But I think it usually does. Maybe something is wrong with how I installed it. I need logical suggestions please. Because other online help just doesn’t make sense at all. Thanks a lot.
