Hi,
Try the following and see if they can find and remove your pop-up.

On-line Virus Scan

Go to one or all of these sites and do an online virus scan.

housecall.trendmicro.com

security.symantec.com

us.mcafee.com/root/mfs/default.asp

Check Malware

Go to http://www.besttechie.net/tools/mbam-setup.exe
and download and run Malwarebytes' Anti-Malware.

If the online scan didn't work, then you can download other antivirus softwares such as AlYac (it's South Korean, but I find it extremely useful). Also, does the advertisement affect your Internet and desktop (weird shortcuts, new homepage, slower connection)? The antivirus99 problem is probably a Rogue adware...

Just try this: http://www.malwarebytes.org/mbam.php

I have seen this problem many times. This software works great.

same software offered in post #2

instruction on its use .
* Double-click mbam-setup.exe and follow the prompts to install the program.
* At the end, be sure to checkmark the Update Malwarebytes' Anti-Malware and Launch Malwarebytes' Anti-Malware, then click Finish.
* If an update is found, it will download and install the latest version.
* Once the program has loaded, select Perform full scan, then click Scan.
* When the scan is complete, click OK, then Show Results to view the results.
* Be sure that everything is checked, and click Remove Selected.
* When completed, a log will open in Notepad.

thats good to hear ,glad you had success ,But i have never heard of search and destroy,I have heard of Spybot search and destroy ,and i don't have an old computer to try it on right now.
how much did they charge you to remove the trojans ! is it totally free!

What is Search and Destroy?

Search and Destroy is another in a long list of fake "spyware removal programs". Most of these infect computers when you are required to download an infected codec program to watch a video online or you may have been attacked by a drive-by installation. In any case, the program "Search and Destroy" tries to use a name similar to a very popular and useful removal tool called Spybot Search and Destroy. It installs on your computer, then proceeds to run a scan and show you a variety of infections that need to be removed. The only problem is my test computer was completely clean of spyware, adware, viruses and other issues when I downloaded and installed Search and Destroy.