I keep getting a pop up window telling me that hackers have complete access to my computer and that

visit a certain website to fix the problem.

i scan my computer with my antivirus programm (which is a very good one) and it says that i dont have viruses.

what should i do?

I keep getting a pop up window telling me that hackers have complete access to my computer and that i should..network security

You have adware/spyware in your system. Do not go to the link and download a good anti-spyware program. You are scanning using an AV and what you need is an anti-spyware. Here are some good ones you can download for free:

http://www.safer-networking.org/

Uber powerful tool which can search and annhilate nasties that make it onto your system. Now with an Immunize section that will help prevent future infections.

http://www.lavasoftusa.com/

Another very powerful tool which searches and kills nasties that infect your system. AdAware and Spybot Search %26 Destroy compliment each other very well.

http://www.javacoolsoftware.com/spywareb...

Great prevention tool to keep nasties from installing on your system.

http://www.javacoolsoftware.com/spywareg...

Works as a Spyware "Shield" to protect your computer from getting malware in the first place.

https://netfiles.uiuc.edu/ehowes/www/res...

puts over 5000 sites in your restricted zone so you'll be protected when you visit innocent-looking sites that aren't actually innocent at all.