just got my pc back after 1 week i paid over 100 pound to get it fixed the same problem has come back again wen i try to log on to the pc it says logging on then it says saying settings

it was working ok last night i went to bed then i turned it on again this morning and it wont log in can any one help me please

i dont want to format the machine that will be the last resort

i am running windows xp home