overclocking question

[BigMoe]

ok I have an 1)abit KT7A moatherboard 2)an AMD 2100 XP "replaced a 1600 xp" 3)mushkin pc150 ram 4)WesterD 80 gig 8 meg cache Hard drive "replaced IBM 45 gig drive" 6)an antec 330 truepower power supply "replaced 400 watt non name brand psu" 7)ati 8500 video card turtle beach sound card and a nic. before any part were replace id get a 160 fsb overclock after i replaced i overclock to 140 no higher "anything over that and computer will post then reboot in a loop" but here is my question when i do any overclocking with new hardware installed it will my hard drive needs defraging but overclocking test work out fine. does this mean my over clock is bad and the info on my drive will corrupt?