How can i fix the blue screen error?

[Damianos Giannis]

When i open my PC, i see a blue screen that sais that it can’t open Windows for unknown reason. I tried reseting it and using Safe mode but it till goes back to the blue screen and i can’t get access to my desktop.
How can i fix this?

 

[ven07]

Any error codes? or a picture of the screen?