help pleaseeeeee

[elyk8]

OK so i am out of school but my friends are still there and want me to make them laugh in class still is there any way i can get a message to pop up on one of the computers at my school any help would be appreciated

 

[MMM]

OK so i am out of school but my friends are still there and want me to make them laugh in class still is there any way i can get a message to pop up on one of the computers at my school any help would be appreciated

Other than hacking..... No

 

[Django Fawkes]

OK so i am out of school but my friends are still there and want me to make them laugh in class still is there any way i can get a message to pop up on one of the computers at my school any help would be appreciated

Hacking isn't regarded as a naughty prank, it's punishable with nearly a life in prison.
There is a way you can do it legally though, but it won't just "pop" up.

You could tell your friend how to get past net blocking and tell him how to send a website to every computer on the network so the whole class have it come up on their screen. But anything other than that is illegal and really not worth it.