2) Use software like “spyware doctor” to protect you against spying trojans ,cookies etc and keep it updated.
3) If you have downloaded a file or setup and after clicking it, if you notice that it is taking very long time to install or is responding weirdly stop the process right there, if it is not closing use task manager to close it and delete the file permanently, it was probably installing a backdoor in your computer.
4) If some software needs you to disable the antivirus or it is suggested such by the uploader please first check this things
- is the software popular and made by some reliable company.
- check if any comments are given at the downloading site always read them to get some hint about the health of the software.
5) If you thing everything is OK then take a chance and download it, if the software requires the antivirus to be disabled don’t disable the antivirus right away, first give it a try with antivirus enabled and see what reaction the antivirus gives if the the antivirus gives it a clean cheat then well and good. mostly the antivirus detects a hacking software as a security threat or a trojan if it does so you may take a try with it but if it detects any other thing then trojan like backdoors, virus, worm, adware, then avoid installing it.
But please note there is no guarantee that hacking software detected as security threat or trojan is totally clean but you have to take chances, because no risk no gain.