I have the same problem. Updated Windows 8 Pro to Windows 8.1 Pro 64 Bit on my new Acer LapTop and my new Dell XPS Desktop. Both Explorer and Chrome have been hijacked by this Yahoo Spigot deal. I have tried EVERYTHING from Malware remover, to deleting all YaHoo references in registry, to refreshing computers, to changing my Windows Profile and NOTHING works. Browsers still default to YaHoo. only browser seems to work is Firefox, but they also have YaHoo version on their site so I stayed away from that one. Dell was aware of the problem and spent 2 hours trying to fix with no luck. I have also tried uninstalling Chrome, but there is no way to try that with Explorer. Please someone help and not get too technical.. I am trying Spyhunter 4 now. It is scanning for free, but I think it asks you to purchase program if you want it to fix the problem.