The built-in defragment tool of Windows is not the best one. I heard that there are a ton of better ones out there - but which one is really good?
Solution 1:
I use Jkdefrag and read good things about it. Can be used as screensaver as well, have a 64-bit version and is open source.
Edit : As of version 4, it's now called MyDefrag.
Solution 2:
For a free option at small shops I've been a fan of Defraggler