Autorun Organizer - Free startup manager with delay option.
WinDirStat - WinDirStat is a disk usage statistics viewer and cleanup tool, inspired by KDirStat.
Startup Delayer - Startup Delayer gives you the power to optimize your Startup Process by delaying applications from starting up as soon as you log into your computer. By delaying the applications during start up, your computer becomes usable a lot faster.
WizTree - WizTree quickly finds the files and folders using the most space on your hard drive. It scans the MFT (Master File Table) instead of crawling the entire disk which makes it very fast.
Autoruns - See what programs are configured to startup automatically when your system boots and you login.
SpaceSniffer - SpaceSniffer is a freeWare (donations are welcome) and portable tool application that lets you understand how folders and files are structured on your disks.