I wish to defragment my hard drive overnight. Are there any pitfalls, dangers, or side-effects for which I should FIRST be aware? Is there the potential to lose files, barring a power outage? Any other things come to mind? If it matters, I am running Windows 2000 Professional.
I’ve had a PC crash in the middle of a lengthy defrag. Things ran hellishly slow after rebooting and the disk was massively fragmented, since the defrag was in the midst of shuffling files around, but it got back up and I ran the defrag again with no problems. I can’t say for certain that zero files were lost or damaged, but I never noticed if there were.
Most defrag programs warn you to run a disk-checking program first; if there are any problems in your files or on your machine, you want to fix those before you go moving them around. Just In Case.
It’s actually quite an important step in keeping your machine running efficiently. I have never heard of a single downside to defragging. Any possible downside would have to be miniscule in comparison to the benefits. A computer networking consultant friend of mine swears that one should always defrag before installing new software. For the most part, I have made a habit of following his advice.
There is a small but real danger in running defrag. The defrag is doing a lot of updating to the FAT tables. If the system crashes before one of those updates completes, that file could end up corrupted. So don’t trip over the power cord, do it at a time when power failures are unlikely, etc.
A well written defragger can practically avoid this problem. So that of course means that the one that ships with MS OSes shouldn’t be used.
Note that this can occur with any program that writes disk files but since a defragger is doing this constantly, it’s more of a concern.
A defrag can also turn up a hidden problem. E.g., a sector of the disk is going bad, it was occupied by an unused file but an important file is moved there. But this is a disk problem that needs fixing. It’s not really defrag’s fault.
Defragging can speed up some computers by amazing amounts. Go ahead and do it regularly.