You are correct, unchecking doesn't delete them.
I started writing a message about the registry editor yesterday but changed my mind. Is it something you want to look at? You can't get into trouble just by looking, as long as you don't change anything there. Let me know and I'll post instructions.
Here is the deal with the startup tab, and it involved the registry. The registry is where Windows stores ALL of the data about your system and software. It contains the info about what hardware you have and what drivers have to be installed for them, all of your configuration settings for all software installed, all of your preferences. When you change the settings in Internet Explorer, those changes are stored in the registry, that's how it knows. When you use an application like Word and use the "recent files" list to open a document, that list of files is in the registry. There it is stored what you want your taskbar and start menu to look like, the desktop pattern you have chosen, etc.
When you install software it writes its own stuff to the registry, the stuff it has to load to run, some of the preferences for that application, etc.
Now with the stuff running... a file on your hard drive doesn't mean anything. It doesn't do anything but sit there and take up space. It can't effect your system. It only means something when you "start" that file (such as when you start an application... fire up your browser or start your word processor for example) OR when some application that is running accesses or calls that file.
Now when you turn on your system, there are some applications that should be running automatically, and running all the time. Your antivirus software, for example. You don't want to have to start windows, and then click on your antivirus software to start it before you begin to do anything. So windows keeps a list of software that you want to start up automatically... and of course this list is in the registry.
The "msconfig" dialog startup tab just displays a list of all the stuff in the registry list that is set to run automatically. When you uncheck something there, it just takes that entry off the list in the registry of things to start. Doesn't do anything to the file, just says not to start that file.
You'ld think it would be easy then to just uncheck the adware stuff and keep it from loading... but the problem is that the adware stuff doesn't run directly from a list, there is some other program somewhere that loads and that program tells the adware to begin. That adware file then may have instructions to load some other files, like those dlls, and if you don't have them (maybe you deleted them) to go on the net and copy them to your hard drive again! Or access them from some other hidden file and copy them back to the normal locations again. I've noticed that lots of adware creates files with random file names that change each time they reload themselves, so you can't just go looking for a list of filenames either. And the problem with the adware, is that even if you delete all the associated files and remove all the registry entries, if you've missed ONE PIECE anywhere it is designed to just load up everything else all over again, rewrite the entries in the system registry, and you are back to square one. So not only does EVERYTHING need to be deleted, but it all has to be deleted at the same time before you reboot. And some files won't delete because they are running at the time.
Now there will be a lot of stuff in that startup list that you don't recognize, don't worry, that's normal. You can uncheck things if you want, some are things that are harmless but you really don't need them loading all the time, they just slow down your system. Some if you uncheck won't seem to make any difference at all, but then at some point you run a piece of software and have a problem with it, that software needed that piece to load at start (no harm done, you just open up msconfig and check the box again and restart). DON'T uncheck anything related to your antivirus or anti-spyware because you don't want to leave your system vulnerable. Things like your antivirus may have several startup entries, if you can't recognize something by the name, look in the "command" column and see where the file is located... if the file is in the McAffe folder for example you should probably let it load.
For anything suspcious, you can just google it. There are a lot of things that are named to sound like legitimate parts of Windows but are actually spyware. If that's the case you'll get a million hits on google explaining what it is, whether you need it or not, etc.
I'm going to do a little searching and come back with more.
Oh one more thing, I should have warned you about the "system config utility" box, that is just to remind you that you have unchecked some of the things there. You do want to let it make the changes. It is probably best for now to let the box appear every time you start up just as a reminder, but if you already checked the "don't show again" box there is no harm. It is just a reminder, and if you choose to change things again all that will happen is that it opens up msconfig for you, but you know how to do that yourself already. If the warning box gets annoying it is ok to check "don't show again"
Sorry I forgot to mention that last night.
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