di ko lang sure ts pero kase parang corrupt na os. restart mo okaya ctrl+alt+delete ka jan, pero try mo to isang way press f8(pero dipende yun kung ano key nang repair nang pc mo)tapos repair computer, pag lumabas yung please select language ek ek next mo lang tapos mag start up repair ka kung meron okaya system restore tapos hintayin mo lang kung matapos kung nag press f8 ka naman tapos walang lumabas install kana nang bagong OS