Yes, as for the mentioned "additional software", we also call 'em "bundleware" even downware, thus you had better: first scan your download; 2nd, perform so-called "Customized Install" mode -- cancel any other options for installing items that U just do not know/ use. The follow video can help U understand the said item better:
1. Perform a virus scan regularly under Safe Mode using an up-to-date security software. Here, I'd recommend Avira Internet Security Suite 2015 to U.
2. Clean potentially unwanted programs (aka, PUPs). Check out "Uninstall a program" >> force remove any other unwanted/ unknown items in the list via an uninstall tool pro if Windows' uninstall utility does not help too much.
3. To avoid foistware and malware infection, DO scan your download via the recommended AISS or Virstotal from Google. Be cautious when you run ad-based installer like some freeware even downware, which can be spread by malvertisements.
* D/L the official avira: http://www.avira.com/en/downloads
* VT site: https://www.virustotal.com/
* How do I get rid of a PUP: http://www.windowsuninstaller.org/forums/viewtopic.php?f=2&t=348&sid=b9a3aaf44b3476181ae7bc3a58c8ddcb
* http://howto-uninstall.windowsuninstaller.org/malvertisement-downware-foistware-and-semi-malware/ what's malvertisement and how to avoid it?
* What's downware? http://uninstallremovepups.blogspot.com/