Adware questions

  While trying to fix a PC problem, I thought I went to MSN's website to re-download a program.  During the download, I received two Norton NIS2013 alerts for "Adware.Crossid Popup.css" and "Adware.crossid VID-Saver.dll".  NIS reportedly blocked the threats and put them in quarantine.  I drilled down through the HKU Registry, to the locations given, and didn't see any listings.  Full scans in safe mode and regular modes showed no problems.  I also ran a scan with the Free SUPERAntiSpyware and it didn't find any probems either.  Can I assume I'm safe and I can continue repairing the PC?