i have two internal hardisk in my pc..each 1tb. the one with os installed does not dissapear..but the other one does. my pc is having serious freezing issues. the hardisk dissapears and when i restart pc it appears again.is my hardisk spoiled? sometimes my pc gives boot issues on startup also. i have a Intel DH67BL Motherboard with i5 2400 processor and 8 gb ddr3 ram with nvidia geforce 460 gtx