maxtor 200 gig/disappearing files

i put a 200 gig hd in my comp recently. a couple of wks later it ate everything in my "program files" folder. i figured that was because i used the whole 200 gigs and am running win98 se. so, i repartitioned as 120 gigs for c: and 80 for d: but the same thing happened again but in addition to my "program files" folder, a couple of other folders had been completely emptied. i thought win98 se could handle any size hd as long as no partition was over 137 gigs and even then, the worst that would happen would be corrupt files.

if that's true, could the hd be bad. what else. (i'm reasonably sure its not a virus.) thx, maxwell