Replacing a HDD once a year is a bit overkill.. I have drives from the 90's that still work fine. they are not lightbulbs but do like any other device have an electronic lifetime or duty cycle rating
I replace them for performance when better come out, not security. For security I use an external array of backup units and also have a secondary hard copy I keep in case of a baclup drive failure. I have only seen (personal) 2 hard drives fail in my entire life and both would have been defects, not burnouts
Richard is right.. Indexing in VISTA is 10x worse than XP... shut it DOWN

and VISTA wont shorten HDD life
Defective SATA drivers can though.. seen that happen before
GRIND GRIND GRIND - CLINK