Creo 2.0 stopped running and dispalying on my laptop computer

Here is the story

I normally work on laptop computer but use a connected monitor as a display ( hp 2035 LCD monitor)

Some days ago, suddenly the monitor lost the view and never came back again.

I disconnected the cable and tried again but no change.

I restarted the computer but no change.

Then, I disconnected the monitor tried running Creo 2.0 on laptop computer.

It looked as if the program starts but no display on the screen.

I borrowed another monitor, connected and tested that way, Creo 2.0 worked.

I disconnected monitor and try to run Creo 2.0, did not work.

I found an hp 2035 monitor just to see if it works, it worked with and without hp monitor until I restarted the computer.

Now, use a Lenovo LCD monitor, Creo 2.0 runs with it but still does not run without a monitor.

There was no problem until hp monitor broken.

I used to work with or without a monitor.

How can I fix this problem?

Thanks!

Emrullah