The free version of this program is in my opinion better than some pay programs. It scans for trojans and malware. An excellent companion to SpyBot and AdAware. You'll need to register and it will send you a code to your email so that you can enable it, but it's definitely worth it in my opinion, and you'll hardly see me giving away MY email address to just anyone online... so you KNOW it's gotta be good.
AdAware removes many adware programs and files. Simply the best at what it does without messing your system up, the free version is a great addition to the security and protection of your computer. There is a pay version, but currently they still offer the free personal version to non-businesses.
Spybot is great at removing those annoying cookies and spyware that AdAware might miss, and vice versa. This page will ask for a donation, but you're not obligated to make one. Definitely worth it in the long run though, if nothing else to support this excellent program.
I used to be a huge AVG fan, and still am, but I found out quite unfortunately that it really doesn't handle Trojan viruses very well. Since then, I've been sold on "Avast!" which is available to home computers for free. The Avast link will take you to the free version's download page. Bear in mind that while it IS free, you need to register it before the 60 day trial limit is up. After registering, they will email you a code to extend it indefinitely.
Though I really only advise this program for computers with a LOT of RAM, it's simply an excellent program. Make your own slideshows, picture web pages, and edit the quality of pictures with this program. The cost : free. Can't beat that with a wet stick, no matter how fast you are.
There are lots of free (and pay) popup stoppers, but I happen to like this one. It auto-updates when you're online, and it fairly feature editable. There is a pay version as well, but I haven't yet found the need to go beyond the free one.
While LC-ISOcreator is a sweet program to create ISO's from CD's and DVDR's, EasyISOcreator lets you create ISO's from files and folders on your harddrive... something LC-ISOcreator doesn't do. Click on the link, then select "English Freeware", then go down near the bottom of the page until you find "XPBURN 1.02 & EASY ISO CREATOR 1.1". Click on that to download. When installing, you'll eventually come to a point where it comes up with a window showing x marks by XPBURN and EasyISOcreator, uncheck the XPBURN box.
This program lets you edit, cut, trim, alter and otherwise manipulate mp3's and wavs, and will also let you convert from one to the other. There are many more features that this program provides, but sufficed to say even if you only use it to trim your favorite mp3 to use as a ringtone, it's more than worth the download.