The only thing I can think of is start your computer in safe mode......if that black pops up if it is still there then it is probably Windows.... since it is new it is probably covered and the place you bought it should fix it....like it is a missing file or a corrupt file...
If it don't pop up you could have a virus you are running an up to date anti virus arn't you?
Try running your anti virus and see if it finds something.
You could also open your start up menu Start, Run type in msconfig then go to Startup and see if there is anything in there that shouldn't be running. If you are not sure.....you can ask the tech which ones you don't need to start.
Things like games, IMs, Office programs, and media players can start when you turn on your computer they are all in your Start menu you can start them when you want not when the computer wants.....and your computer will run better if all that stuff isn't starting also......
