Soluto claims to be "anti-frustration software". It lets you see the time each application takes on boot, then for each choose whether to keep it in boot, remove it, or delay it (e.g. if you don't need your Dropbox sync to be up immediately, you can delay it so that your boot will be faster and Dropbox will still be started automatically later). You can also see the choices of other users around the world.
Notes and implications:
- The interface is now fully web, so you need your data to be sent to their servers. This might be a problem if you are concerned with privacy (the time when it fully ran on your machine is unfortunately over).
- Soluto needs an agent to be running on your computer (if only to start delayed programs). That one you won't be able to remove from boot (or you'll most features that make Soluto an interesting solution).
I am aware this solution will not please everybody and I guess the other answers would make most people happy (I am thinking of removing it myself for one of those; I already use CCleaner in conjunction). For the sake of exhaustivity, though, and to leave you with a choice…
- Free (gratis): not fully-featured and for a limited number of devices (5 if I remember correctly), but yes.
- "Manage" means ability to permanently remove any given set of programs from being autostarted: as for any software of this type, yes until the program is updated and updates the registry again.
- Comprehensive: yes. Anything that is loaded on boot appears here.
- MUST work on Windows XP: it's been a while since I don't have an XP. I don't find the info on the website, but in my memories, it only needed a sufficient version of the .NET framework to run. Works on 7 and 8 for sure.
- Strongly preferred: Tell me exactly WHICH of the multiple startup options a given autostarted program originates in, before I disable it: I think that's a no here, but I cannot access it right now to check.
Since everything is managed in a webapp, if you feel like a good soul, you can also manage your parents' or your boy/girlfriend's computer.