u said "KARAAN" - i would suggest visual inspection naa ba gurot na capacitors, sunog na parts etc. then try cleaning internals, remove dust and other foreign materials. insert and reinsert data-power cables and the likes. kung ok na, try booting up again. if dili musulod windows-reformat. kung problema gihapon like bsod etc, check memory or try replacing with good working one, kung mag ungot2 bsin harddisk guba, try running hdd related diagnostic apps from manufacturer.
kana lang usa. GOOL DUCK!