The messages you are getting are likely badware wanting you to download or purchase their products. You might have them on your computer already. Don't download anything that tells you that you have a problem and that you need such and so program to fix it.

Go to http://majorgeeks.com and look for Spybot Search and Destroy, Ad-Aware, and the Microsoft beta anti-spyware program under the antivirus tab. They are free home editions and work well. Be sure to search for updates after you have downloaded them. See what they find and how much they can delete or fix.

It sounds like you already have "Spyware Blaster" It is different from the above in that it blocks a lot of junk from even making it to your system. Others might have other suggestions, but these programs work well and all are free. If your problems continue you might need to download the HJT file and run a scan with it and post it on the HJT forum for an expert to analyze.