Windows Defender Warning every time I switch on.?

The problem is Trojandownloader:Win32/Zlob. Windows Defender asks me to review it, then I click the box to say Remove. But it doesn't work. Every time I come back to the computer I get the same message. The level of threat is severe. How did it get there and how do i get rid of it? Also, a box keeps popping up in the bottom right hand corner telling me that there is an Outbreak Alert. I seem to have spent a small fortune on security protection etc etc. Any suggestions?

Windows Defender Warning every time I switch on.?virus protection software

That particular variant of the Zlob Trojan is in your temporary internet files so it keeps reinstalling itself. When Defender catches it, delete it then go to Internet Explorer and delete all of your history. If you have Firefox, clear the firefox one too. If you see that it is still showing up, get another scanner such as Kaspersky (the best on the market) I personally had this problem about 1 week ago and Kaspersky got rid of it quickly and easily.

www.kaspersky.com

Good luck!

Windows Defender Warning every time I switch on.?adware

i suggest you do a scan with windows live online scan, it takes a while but is worth it http://onecare.live.com/site/en-us/defau...

also i suggest getting an antivirus, you can get a free one from here: http://wiki.castlecops.com/AntiVirus_Com... i use antivir but that site reviews all 4 and compares them side by side. i would use avast after antivir but choose for youreself
Try remove the Trojan manually, go to desktop%26gt;search%26gt;