About CCleaner and Autoruns:
How to fully de-gunk a PC of Crapware
TCPView (go to bottom of page to download) gives an overview of all connections. By double clicking on a listing the program using the connection is listed.
I found the reference to this program at alt.fiction.original of all places
A nice list of processes,what they do, and comments about them at neuber.com
Find another process list at http://www.processlibrary.com/
There’s also Process Explorer which gives an overview of all processes running and where they’re running from. Again, go to the bottom of the page to find the download.
And then there is this little program that will check the Start Menu and the System Registry for items that load at startup
Then there is HijackThis. And a friendly tutorial on using HijackThis