First off, Norton in my opinion, is complete bloatware...uses a lot of system resources.
There are a lot of useful freeware antivirus software such as A squared Free edition located here:
|MG| a-squared (aČ) Free edition 3.1.0.20 I have found it to be quite useful. (finds same amount if not more than most norton products) or AVG Anti Virus, both work really well.
|MG| AVG AntiVirus Free Edition 7.5.516a1225
try downloading either one of those and then boot into safe mode (usually F8)
run one of the suggested programs and see what it finds ( i have had this problem before and it usually helps with some of the cleaning process)
an expert will assist you with the hijack this log, that is an area im not equipped for.
GOOD LUCK!