My company has just had all the computers upgraded. While the IT guy was in the office I asked him why when I swtch off my computer at home a box would pop up and say if I switch off my computer other users would lose the signal ?
He told me that other users were using my computer to down load music and films resulting in my computer being very slow.
That's something I have noticed how slow my computer has become. I have firewall so obviously it's not doing it's job.
The it guy recommended a free fix, spy wear through google.
I have bought many things on-line. makes you wonder what these hackers can get out of your hard drive. Scary stuff indeed.

