You might have either a PROGRAM or a VIRUS installed on your computer that could be causing the parasite infection in your system.
Please try the instructions below, they might help you fixing your problem and the information below will give you directions to find the cause of the parasite infection.
Please MAKE SURE you have an updated anti-virus software running and re-scan your system.
Do you have any program that you do not use or that you cannot identify or freeware, shareware, or file-sharing programs (example: Screensavers Programs, Search Bars, Kazaa, Limewire, Morpheus, iMesh, etc.)? Most freeware, shareware, Free Screensavers, Search Bars and file-sharing programs have spyware built into their programs. One of the reasons you may still be getting popups is because you have these programs and need to uninstall/remove these programs from your computer.
It is also a must to clean up your browser every time after removing parasites using anti-spyware program from the recommended anti-spyware list.
To Clean up you browser, if you use Internet Explorer, click the tools menu, and then click the internet options menu item. Change the homepage to whatever you want the default page to be (ie www.google.com). Click delete cookies, delete [cache] files, and delete history. Click apply. You may also want to increase the security settings on your browser to block potential spyware and adware as you browse the internet. Click the Security tab, and customize the settings so that it prompts you before saving files and installing programs to your computer. You don't have to disable them, or change them all, but I recommend you set all ActiveX type things at least to prompts, since ActiveX tends to take the most liberties if you enable it. With a high security setting on your browser, you may lose the functionality of some sites, so it is recommend that you adjust it to suit your needs.
Also, it's a must to go into your control panel, select add/remove programs, and uninstall any programs that you don't recognize or don't use. You may have to go into safe mode to delete some of these.
Even with all this, I recommend running your anti-spyware program at least once a month to ensure that your computer is clean of spyware and addware. If you don't want to remove any file sharing programs or change your browser setting, I recommend running anti-spyware more often, say every time you start the computer.
If you go to the same web pages every day and those are infecting your computer with Spywares/Parasites, you will need either to run your anti-spyware software every day or change your browsing habits.
Also remember that there is not such thing as a free product. If you download a free product onto your machine you are going to pay for it somehow and usually you'll get massive annoying advertisement or you'll have your machine damaged for a program that was not fully tested.
Hope that this was helpful...