How to remove adware and spyware for free?

Ok, first to explain few things...
There's nothing bad in commercial anti spyware tools, but this post will be focused only on free anti spyware tools. Because it can yield same results as commercial tools, and is definitely more fun and educating
.Here we go...

ingredients needed:

• Process explorer
• HijackThis
• AdAware free edition
• or Spybot search and destroy

Process Explorer and HijackThis are only diagnostic tools while AdAware and Spybot SND are actual cleaning software...

Process explorer - This is basically more advanced task manager (you can open default windows task manager with Ctrl + Alt + Del). You can view all running processes on your PC, and more importantly, you can see their actual filenames. If you see something that you think shouldn't be running, or you're just curious about what does what, you can just google filenames you see in the process list and get quick info about it (right click on process and choose "google" from the menu that pops out), you can also find phisical location of the file thats running also by right clicking desired process and choosing properties from the menu. You can quickly and easily identify and
kill malicious software running on your PC using that method.

HijackThis - While process explorer gives you control of programs running on your machine, HijackThis gives you control of services and applications that are set to run every time you PC starts. You cant prevent from running almost anything that way INCLUDING some windows components, so be careful. This particular tool has saved my ass a few dozen times and it's completely free... The easiest way to use it is to run it a few times and scan your system while it's in a good shape... and after malicious software gets on your PC you just scan again and look for newcomers compared to your last list, that way you can easily prevent them from running next time you start your PC (keep in mind that you will actually have to kill their process before removing them from this list otherwise they will just add themselves to the list again, you can use process explorer to kill them)

Spybot SND & AdAware - i will not describe each program separately because they both preform quite similar.
These are automated cleaning tools and are among the very best anti spyware products. There's not much to say about using them too. You install them, let them update from the net (they need definition updates otherwise they soon become useless just like antivirus software), and then you let them rip and shred scum that lurks somewhere on your disk.
For the best cleaning success always scan from the safe mode when possible. To enter Safe mode you need to press F8 when windows start loading (or little sooner) and then choose "Safe mode" from the menu that pops up :)