userinit.exe

Well i have seen many a people(esp. my hostel frnds ….itz for you ) confused by a thing called userinit.exe….what is it aactually? Is it a visrus or a windows process ?if  its a virus then how to handle it …..huf……
let me give the formal description of it
(1) Userinit.exe is a key process in the [...]