I looked for it on google, downloaded few but they aren't working, do anyone know some working links??

 

Here is the link for the download page for the Proteus 7 demo:
http://www.labcenter.com/download/prodemo_download.cfm#professional

The demo program is free. It differs from Proteus Lite in that it does not allow you to save, print or design your own microcontroller based designs (you can however write your own software programs to run on the existing sample design suite for evaluation), but does include all features offered by the professional system including netlist based PCB design with auto-placement, auto-routing and graph based simulation.

If you wish to be able to save, print, or design microcontroller based designs, you must purchase one of the student or commercial versions. There are no "free" versions other than the above demo available.

This forum will not tolerate requests for illegal copies of commercial software, so please do not ask for them.

If you have attempted to download such illegal copies, your computer is probably infested with viruses or other malware, that may prove difficult or nearly impossible to remove.

 

many thanks

 

I'd recommend you run a virus scan though, just in case.