How do i fix black screen after boot?

[chrisepic]

Whenever i start my laptop after it says starting windows and then turns into a black screen it doesn't even show the login screen and stays at the black screen for like forever!Sometimes it doesn't happen but even if it doesn't happen when i login to my pc after 5-8 minutes it just starts lagging and freezes and i have to restart it and go threw all this!please help i don't think i can afford another laptop i'm only 14! 🙁

 

[NihilistD]

which version of windows do you have?