BleepingComputer.com: Computer restart over over again

It was normal day got back home want to some games on my computer i turned on my computer go to my user like 15 mins it restarts so i go to my user again its in safe mode and all the corners shows "safe mode" it restarts again in just 1 min it goes to normal mode but it restarts much faster a bit like 10 mins then i do it all again it restarts even faster in normal mode now in 3 mins like that but if i unplug the plug of the modem to the computer it doesnt restart and i cant use my security at all even when offline it show a bright red pop up in the background showing a nuclear logo saying that your security is under protection bla bla bla and stuff .HELP PLEASE

Sounds like you may be infected.. I would suggest posting here.