You maybe got spyware or malware attacked. If you have another user login, then log in with another user and down load Anti-Malwar (Malwarebytes) . or go microsoft website down load " Microsoft Security Essentials" and run a scan. after scan and delect the spyware and reset the internet connection..........go to Internet Explorer. select Tools>Internet Options>Connections>LAN Settings> UNCHECK Proxy server and select Automaticall Detect settings ( This is why they will force you 強制使用某個網站當首頁) Hope this can help you solve your problem.
