Every time i log on and go to my yahoo page this window keeps popping up that says internet security

i know this is a pay for security site and i dont want it. i have norton security. i have tried to delete this security site from my files but i think i have screwed up my computer because it does not perform well any more,, can you please tell me how i can delete this (spy heal) from my computer ??

Every time i log on and go to my yahoo page this window keeps popping up that says internet security,,?vista

You should scan your computer with AVG, it is much more effective than Norton Internet Security. Also scan your PC with Spybot, Ad-Aware and Ewido. Download them here (they are all free): http://www.cybertopcops.com/free-downloa...

You can also try the following page:

http://www.cybertopcops.com/malicious-so...

Every time i log on and go to my yahoo page this window keeps popping up that says internet security,,?antispyware

It's worth getting an expert to check your computer out at:

http://www.webuser.co.uk/forums/ubbthrea...

Register, go to the Hijack This Forum, read the instructions on how to post a log, give a brief description of your problem (like you've just typed) and post your log there. The guys in there are fantastic and trustworthy and will guide you through in getting rid of anything nasty from your computer. Good luck!
I would guess that your comp is infected.I have found norton to be useless.i do not think anything your done has slowed down your computer.i think you have malware installed on your computer.microsoft has a free scan.If that doesnt help you may need a professional.
Try to remove it completely from Add/Remove Programs.