Every time I turn on my PC the main monitor shows but the second is detected, and acts like its working but the screen is blank. When I restart my PC it works fine... The screens are the same size, same response time, same refresh rate and same resolutions, any idea's?

Update video drivers? I know that it probably wouldn't be the solution, but it's what I'd do first.

All the drivers are up to date.

Strange situation. Everything that I find where a monitor is detected but has no diplay they can't get the monitor to work after reboot.

What OS are your using?
Are you using any adapters, like HDMI to DVI?
Are they both on the same graphics card or is one connected to a graphics card and the other to the motherboard?

I'm thinking that is that it's something with the OS. I'd start changing the OS display settings when you first boot it up and the monitor's blank. If you haven't done so already, you might also want to check the settings on the monitor to make sure that it isn't a power-saving feature.

commented: It was a power saving feature, Thank you... I'm feeling abit silly ;) +3

Windows 8
I am using DVI>VGA for the main monitor and Display Port > DVI for the second
Both connected the GPU.

I tried changing the blank monitor to the main screen when it wasn't working and that still didn't make it work. I know there is nothing wrong with the screen as I have used it for ages for my main screen. It is a very strange problem.

Thanks for the update. Glad to hear you got it working.

Sometimes just talking it trough with someone helps a lot.