Formatting probem

Question

i have problem wen i try to reformat my pc bec i have 3 OS use but it cant read it to my cd rom so untill now i cant reformat my pc..but my cd rom is okie i can listen to the music and watch movie in my pc ...but wen my cd in OS cannot read it....wen i scanned my computer i see result on FILE: boot sector of disk RESULT/INFECTION: change PATH: C: wat is that mean ?i think that is the problem why i cant reformat my pc ..i hope u can help me..