im always wary of any of these so called 'pc doctor/repair' type companys,i have heard so many stories where they couldnt sort it and then suggested the motherboard/memory/HD was damaged as a last resort.
I stopped someone throwing a perfectly good PC in a dustbin because of misleading advice,apparently the motherboard was burnt out & the hardrive faulty, a factory restore by pressing one of the F keys solved the problem !!!
Its a bit like repairing a car, word of mouth or recomendation from somebody.