A godsend for people like me who mess up their computer all the time.

Regrun watches for changes to the registry, the auto-started programs, system files, drivers etc. Prevents stupid programs from autostarting themselves, and protects against trojans etc.

It comes with a registry editor, a process manager etc. It makes backups of the system configuration. It allows you to do a clean boot (halfway between full boot and safe mode). It allows you to automatically start programs with delays etc.

All those little tools sound like nothing much but the whole just turns out to be absolutely essential.