Recently 2 of my relatives computer were infected by virus, when they downloaded realplayer software ? I have.?

It is safe, the site is showing green for wot and site advisor. What exactly did they both download ?

Realplayer has sucked for a very long time now... I'm not terribly surprised, to be honest. It is a legit media player, but you're better off getting a codec to play Realplayer files. I'm interested to find out where they downloaded it from. It's ALWAYS a good idea to make sure that you go to the company's home page when trying to download software. I don't really even recommend download.com or filehippo because they just sit back and rake in cash from the 10 billion ads on their sites. cnet is a good place to look for downloads. It's a lot more straight forward and you can tell exactly which download button is the one you want and isn't a crappy adware link.

It all depends on where they downloaded it from. If they downloaded it from the official site, they should be fine. If they downloaded through torrents/file sharing sites (unsafe), then its more likely that it is the cause.