My HD was in degradation since i bought it (that SMART message at startup) "Pri Master Hard Disk: S.M.A.R.T. Status BAS, Backup and replace. Press F1 to Resume" So my trick was check what was the exactly defective sectors, a and let it ranges inactive(i.e, if the defective clusters were on 2357MG, i would let the range from 0 to 5 gbs inactive). It worked on XP and Windows 7, no freezes at all. But now, windows 8 has some kind of native diagnostic that is showing sometimes, saying something is wrong with my HD and i should use another HD, and sometimes it just freezes windows 8. Is this a new service on windows 8? can i deactivate it? EDIT: When it showed up again I had the option to dont show the message again, so i did. I just remeber now.... what i did was exactly what my example, My disk0 partition 1(0 gb to 4,5gb) is inactive. I installed Windows 8 on disk0 partition 2, and when i choosed it on Windows 8 install gui, it said it wasnt possible to install on disk 0 partition 2(but it did) because it could bring me problems(in other words). It can be the problem? Thanks!