Hello monika, the question comes up often here please see the link and note ravencajun instructions about running the 3 programs, about the 3rd or 4th post down in the thread.

Here is a link that might be useful: Help with xp2008

yes you need to get these programs and follow all the steps do not skip any.

http://www.atribune.org/index.php?option=com_content&task=view&id=25&Itemid=25
Please download ATF Cleaner by Atribune from http://www.atribune.org/index.php?option=com_content&task=view&id=25&Itemid=25 . Save it to your Desktop.

Run ATF Cleaner

* Double-click ATF-Cleaner.exe to run the program.
* Click Select All found at the bottom of the list.
* Click the Empty Selected button.
* Click Exit on the Main menu to close the program.
* Shutdown/restart the computer.

superantispyware free, download install update it run full scan let it clean what it finds
SUPERAntiSpyware

Malwarebytes' Anti-Malware
Please download Malwarebytes' Anti-Malware to your desktop.

* Double-click mbam-setup.exe and follow the prompts to install the program.
* At the end, be sure a checkmark is placed next to 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

let us know how you are then.

what antivirus program do you have on your pc and is it updated?
what antispyware do you run on your pc and how often ?

what firewall do you have on your pc?
If you do not have these things you need them, they must be updated and run regularly.
do you have all the latest windows critical updates? if not please go to windows update and get them installed.

Thank you so much it worked, you're awesome.

I use AVG 7.5 and it updates automatically every day and I run it twice a week. I also have Spybot Search and Destroy and Ad Aware which I update when I run it twice a week.

As far as I can tell it's the windows firewall. Windows automatically updates on my pc. Do I need to look for additional updates?

Also, should I run the SuperAntiSpyware, Malwarebytes' Anti-Malware and the ATF Cleaner in addition to the other things I have?

Thank you again for helping me.

Monika

yes Spybot and Ad Aware are not as good as they once were, I really don't use them much at all anymore I instead use the Superantispyware and the malwarebytes. Yes you can keep and use those 3 programs weekly, just remember to update the ones that need it before doing a scan.

If you are only using the windows firewall you might want to consider getting one of the free firewalls and use it rather than the Windows one it is not that great. I use zonealarm pro but they do have a good free version.
ZoneAlarm Guide and Tips

You did not say if you have xp or vista?
If you have xp I would also recommend getting spywareblaster which you just update once a week and hit enable all protection, no scans, it works in the back ground.
SpywareBlaster 4.1

Glad you are clean you might want to read this about that infection.
http://www.theregister.co.uk/2008/08/22/anatomy_of_a_hack/print.html