I know it's not, but Microsoft Security Essentials flags the file "insthlp.dat" in the screensaver's install directory as a generic "Spyware:Win32/Agent" threat, and won't let me ignore it. It says it "installs browser modifiers". The screensaver still functions after quarantining this file, but I'm a little disappointed by MSE's overzealotry lately.

Scan the file "insthlp.dat" with VirusTotal if you want to be sure it's not infected. It's probably a false positive. VirusTotal, now owned by Google, is a web-based antivirus service that uses 55 different scan engines to analyze any file you upload.

MSE isn't very reliable. If you're looking for a better free antivirus, take a look at Avira Free Antivirus 2015, but avoid installing Avira SearchFree, which is nothing but a disguised version of the Ask Toolbar (a spyware). Other than that, it's a nice antivirus, lighter than the latest releases of Avast and AVG. If you want to spend some money and get a commercial one, I highly suggest ESET NOD32.

Well, this was an issue from three years ago. MSE has been updated many, many times since then, and I've started using MBAM as well. And I've finished with the game so it's not even installed on my system anymore.

Please disregard this post, I didn't checked the date before I posted! Oops! ;-)