Randomly restarting noisy messed up pc

Hey,

Im running windows XP.
2.40 gigahertz AMD Athlon 64 X2 Dual Core
Board: http://www.abit.com.tw/ AX78(AMD770+SB600) 1.x
My computer sometimes just randomly restarts.
I have installed no new hardware or software.
Also it wont shutdown (it says windows is shutting down, that screen dissapears, and leaves me with a blue background and frozen everything) and there is a noise like a very fast ticking noise every time i scroll down the screen, in a games menu etc. I Dced the speaker and nothings changed. Keyboard keys also randomly stop working. I have a Zboard Merc gaming keyboard. I find pressing the Zboard button opens up windows media player and the keys work again. Also windows media player doesnt show a picture unless i have nero showtime essentials open playing a movie (paused or playing).

These problems are very annoying.

Any help would be appreciated
TIA