I dont get it with these 'freeware' to remove the spyware ffrom my computer?

i must've downloaded and deleted so many frickin freeware cuz well,, hehe, i dont want to spend any money, like AVG, and spybot(except i cant use it) butif i absolutely HAVE TO, i will. it's so annoying how i go on the websites that ppl reccommend and download the software. when i finally use it, the software scans it and all, but wen it comes to the point of removing the spyware, it says i have to register or enter a license key. if i click on register or anythign else, a site pops up and tells me to buy it. it's either i dunt know how tuh' use the program or i just have to go buy it to get full protection.