windows xp., -  Run a complete scan with Norton. and it gives a negative result
 no viruses, spams, or spywares.,    I then run a STOP sign free antivirus scan and it gave me a result of  7 cookies and 3 trojan infected., so now I am confused because
apparently Norton is one of the best reliable software there is.  so which way should I go. Nah Norton is far from one of the best antivirus programs out there. It is one of the biggest resource hogs and one of the most expensive though.

That being said I wouldn't trust Stop Sign either after reading what other people are saying about it.

If you're looking for a good antivirus program then you should try AVG. It has a good detection RATE, doesn't TAKE up a lot of computer resources and it's free.

But since you're computer might be infected (according to stop sign at least). You might want to scan your computer with an online virus scanner.
Here are LINKS to a couple of good ones:
Kaspersky Online Scanner
F-Secure Online Scanner
Norton and Stop Sign are programs to STAY away from.  Like Deerpark says, AVG is definitely the way to go.I certainly hope you haven't given Stop Sign their $99.00...

If so post back...there are ways to convince them to refund it.Certainly did not give any money to them., thanks to you guys., I went for AVG,  SPYBOT S & D. I have resolved that challenge for now. thanks  again.Glad we could save you some of your hard earned dough !AVG is hella yeah better then Norton whatever