+ 0 Votes Depends on the hardware ps.techrep 4 years ago I may get flamed for this, but at work I used to defrag our server shared data volumes every month for more than 5 years, and never had a drive failure. It might have helped that they were SCSI drives.I have one of these 8 year old retired servers at home, and run JKDefag with scripts DAILY. The daily scripts just defrags files, the weekly and monthly scripts are more thorough. On my XP machines using IDE, I run a defrag each week.Some observations:1. If you try to keep your C: partition clear of everything by system files, not only is the partition much smaller, but it needs less defragging work. If you keep your data files and applications on separate partitions, the same is true. 2. I have quite a bit of application churn, and notice that the applications partition and the Windows directory of my C: partition become far more fragmented than my data partitions. 3. I've never experienced a drive failure due to "wearing out the drive". Those that failed were due to PCs without real surge protection, and most had cases full of so much dust, that they looked like there were sweaters inside them. Every one of these was sitting on the floor under someone's desk in a carpeted room.So, unless you plan to keep using the same PC and hard drives for much longer than 5 years, you can ignore your girlfriends' local retailer. Install a real data device surge protector (better yet a conditioning UPS), clean out your PC physically as well as logically, and defrag away.