said by sivran:
I got games. I play them. I also frequently load up some large files--truecrypt file-based volume, movies, etc.
I also defragged a friend's laptop after three years of neglect. No improvement.
Stuff like movies you won't notice unless it's extremely bad, since players use buffers. Disable buffering and if the movie is fragmented enough you will have issues viewing it without pauses.
After 3 years of neglect, fragmented files is probably the least of the issues with your friends laptop, or the fragmentation isn't that bad.
Defragmenting will also only yield better load times if the files that are being loaded are fragmented, as well as how they are fragmented. You take a 1GB file, and slip in a 24KB file at the 500MB mark, thus fragmenting the file into 2 pieces, there won't really be any performance hit beyond 1-2ms. Now split that file up all over the drive to where for a single file it has to basically go over the entire disk platter...
Defragmenting can absolutely improve loading times, and oftentimes not just by miniscule amounts. It's not even remotely comparable to registry cleaning.