And the CNET.Download team virus check all the software listed, so it will be virus free, but of course you would always check any downloaded installation file yourself for viruses before installing the software anyway.
There's no reviews, although 671 people have downloaded it. But it has been available since 2005, so I am not sure that could be considered popular.
Strangely, when I visited the software developer, http://www.xequte.com/, I can find no mention of this I Fun Viewer, but the site itself seems malware free.
It seems you have tried it before, (you said you really like it), so why not install it again?
One thing though, it is not marked as compatible with Vista. You don't say what OS you are using.