Helping people with computers... one answer at a time.
Free downloads are a lucrative way to get games, programs, and other things at no cost. But sometimes free downloads carry a very heavy cost in the form of spyware, viruses and more.
If i wanted a free download, say a risky file from bittorrent such as a game, would my computer be safe if I downloaded it directly to a CD or DVD?
In a word, no.
It's not where you put your free download that's risky - it's what you do with it next.
Here's what I recommend...
My first recommendation is actually quite simple: don't download it if you think it's risky. Really ... if it turns out to be a problem, is it really worth it? Remember that in the worst case scenario a virus could cause you to lose everything on your machine.
I ask again, is it worth it?
Having asked that, I know that all too often the temptation is simply too great.
It doesn't matter where you download to. A free download such as a game or other tool is totally benign if all you do is download it.
But of course you're not downloading it just to have the download, you're downloading it so that you can run it and play the game or use the utility, or otherwise make use of whatever it is. And again, it doesn't matter where it was run from - hard disk or CD - once you run it, if there's going to be trouble, that's when it starts.
So, if you must download and run something that you think might be risky, here's how I do it:
Download the file. NEVER say "run from this location" or the equivalent, but rather always "save to disk". In your case, if you're using bittorrent, "save to disk" is what you get.
Do Not Run The File
If the file is a ZIP file, extract its contents.
Do Not Run The File
Fire up your Anti-Virus program, make sure that the virus database is up-to-date, and perform a manual scan of the folder that contains the file you just downloaded, and/or the files you've just extracted. Make sure to scan the entire folder and all of its sub-folders.
Most all anti-spyware tools have components, sometimes optional, that monitor for attempts to install spyware. Make sure that the anti-spyware database is up to date, and that those components are running.
Run the program you've downloaded.
Once it has installed or run once, run a manual spyware scan in case the real time components failed to detect something.
An additional layer of protection is to have a "sacrificial machine". Meaning that you still follow all those steps, but on a machine that you disconnect from your network after the download, and that if all goes horribly wrong, you can reformat or restore to a previous state.
As you can tell, making sure a download is safe is a bit of work, and many people simply fail to take the extra time to do it. The result? Many computers are infected with assorted viruses, spyware and other maladies.
If you must download something that isn't 100% trustworthy, then definitely take the time to protect yourself.