How do I know if I have a Trojan Horse on my PC?

I have Norton complete firewall and virus protection. I use a cable modem
which I turn off when not using.

I've run scans using different software and show no virus. But, could I
still have a Trojan Horse which could cause problems?

When I boot up the PC (using XP Pro), it finishes booting up then boots down
without my effort. I then have to reboot in normal mode to get it to reboot.

And, someone just emailed me writing that I have invaded his mailbox. How
can i find out if my computer is sending emails to people without my
knowledge?

Thanks for any help here. I am not a computer expert when it comes to virus
problems.

steve

Steve Shapson wrote:

> I have Norton complete firewall and virus protection. I use a cable modem
> which I turn off when not using.

OK, but that's no reason at all to feel secure.

> I've run scans using different software and show no virus. But, could I
> still have a Trojan Horse which could cause problems?

Of course there could be a trojan or any other malware on your computer,
*although* your "security" software doesn't detect anything.

> When I boot up the PC (using XP Pro), it finishes booting up then boots down
> without my effort. I then have to reboot in normal mode to get it to reboot.

Probably a windows problem, perhaps hardware / driver.

> And, someone just emailed me writing that I have invaded his mailbox.

Please describe in detail!

> How
> can i find out if my computer is sending emails to people without my
> knowledge?

Make a startup- and process list using Hijackthis and Spybot Search and
Destroy (>Programs >Spybot Search and Destroy >advanced mode; if
running, choose >Tool >Process list >Export; save the file as txt and
post its content here.

--
Regards, Torti