Windows vista wont start up!?

[xweded]

when i power my vista computer it run like it would usially do... when it gets 2 the sellection, with start up normaly, safe mode... etc. my arrow keys wont work neither enter so i need 2 wait for the timer 2 go down again??? then it continues 2 load as usial but then instead of going 2 the desktop it restarts itself and does it all again...? >.<..

o and btw... b4 this all happened a message came up on my PC saying "Your computer will restart in 1 minuite, save your work now"

how do i fix this fast and simply