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: ...

Back in the bad old days of computing, hard-drive defragmentation was a big deal. You needed a quality third-party “defragger,” and you needed to run it regularly—at least once a month—to ensure ...