System performance myths

Cleaning the windows registry on a regular basis.

Defragmenting filesystems regularly. I know people who spend more time watching the progress of the NTFS defragmenter than they do anything else.

Especially when people keep forcing it to re-run to try coalesce the free-space, when doing so just means files immediately gain a fragment as soon as they next extend.

The only filesystems that really need defragmenting under normal circumstances are FAT16/FAT32. ext2/3, NTFS, and most modern filesystems usually only see serious fragmentation (to the point where the performance hit is measurable) after years of active use or when they get close to full.

Memory Optimisation programs,

Registry Cleaners,

Registry Optimisers,

Basically anything that says it can speed up your computer dramatically.

A perfect example of this would be the advice to run Nightly anti-virus scans of all files. While I think that scanning all the files periodically is useful (I do it once a week). I also feel that doing a virus scan too frequently on "all files" is detrimental.

Virus scanners check all the files which are accessed. So once you have scanned the entire contents of your hard disk once, theoretically under these conditions, you should never touch another file on your system without the AV software also inspecting it first. So during this "static" state it is unnecessary to keep scanning everything. The system must touch/open/access/copy a file for a virus to end up on your disk. So that being said...

Continuing to scan exhaustively will only result in wearing out your drive before its time.