sync[1] Trojan Malscirpt..js Virus

Whenever I pull up IE on my Windows 7 laptop I get this goddamn annoying message that comes up saying sync[1] is being assessed and then saying it's unsafe and has been removed. Has been doing this for about a month now and it's really doing my head in now. I've used the Norton Power Eraser several times and it hasn't done squat. I refuse to have to buy a new laptop or reboot to manufacturer's settings because of some Trojan virus from Javascript that I don't even know how I got.  Someone useful actually help me to get rid of this please. Norton are useless for this one. Normally don't have any issues with Norton until this turned up.