Onlin [e] Guid [e]

For the last couple months I've been troubleshooting a vexing problem on my new quad-core HP desktop: Roughly once per week, the machine would start running as slow as molasses.

And I mean slow: Programs would take several minutes to load, and even simple activities like switching browser tabs were maddeningly sluggish. The system slowdowns appeared to be due to excessive disk activity, at least based on my observations of Windows' Resource Monitor (CPU and RAM activity were more or less normal). Curiously, this behavior would last for several hours, and then the system would be back to normal.

Knowing a thing or two about PCs, I tried all kinds of remedies. I checked for viruses and spyware. I ran memory and hard-drive tests. I uninstalled a few potentially culpable (or so I thought) programs, including HP's junkware. I even disabled a few Windows services (like Search and SuperFetch), which some fellow users suggested could be to blame.

Nothing worked. I even went so far as to wipe the hard drive and reload Windows (Vista x64, in case you were wondering), even though the system was barely a month old. That did the trick--for about a week.

Disk Defragmenter Issue or Vista Glitch?

This got so irksome that I started venting about it on Facebook. And that's when an old high-school buddy (you rock, Scooter!) came to the rescue. He suggested I check Windows' Disk Defragmenter. Sure enough, it was set to run on a schedule, and the last time it ran matched up with the most recent slowdown.

Suddenly it all made sense: The non-stop hard-disk activity, the out-of-the-blue recurrence of the slowdowns, and the eventual return to normal. The only thing I couldn't figure out was why I never spotted Disk Defragmenter when I was poking around Task Manager. It was as though it was running so far behind the scenes as to be invisible.

I've since disabled the feature, and to date I haven't had a single slowdown. Granted, it's barely been two weeks, but I'm 98 percent sure this was the root of the problem.

What about keeping my hard drive defragmented? I can do that manually, once a month or so, on my schedule. In the meantime, where do I file a bug report with Microsoft? I suspect this might be a glitch in the 64-bit version of Vista.

Alternatives to Vista's Defrag Tool

Hard drives do indeed get fragmented over time, which is why defrag utilities exist. I'm so done with Microsoft's, but in an impressive display of perfect timing, our own Preston Gralla just wrote up a splendid (and free) alternative: Smart Defrag. Most attractive feature: "Auto Defrag, which defragments your hard disk only when you computer is idle, so that you don't interrupt or slow down any work."

Preston also recommends Defraggler, which he says is better than Windows' own defragment utility in several ways. First off, this download scans your disk faster, which anyone with a large hard disk will certainly welcome. In addition, it can defragment individual files instead of your entire hard disk, and it's more entertaining to watch than the built-in utility.

Need even more options? Auslogics Disk Defrag is another popular freeware defragger. You might also want to browse our file collection, "Low-Cost Utilities Defrag RAM and Hard Drives."