Marami pwede culprit.. need to isolate problem sir e..g
1) Baka infected ka malware - so need mo check and linisin via ccleaner, , Sypbot Search & Destroy, and the like
2) pag gamit mo ba browser specifically IE dun siya nag mamanifest? if yun, e try mo mo muna gawing mga default settings before ka magconnect sa inet.e.g. yung home page gawin mong blank, disable mga addons.. deletin mo mga temporary internet files..
3) pwede mo din try mag safe mode muna..
Shutdown the notebook and then start ulit and press F8 while booting para maka pag Windows Recovery Console. Pillin 'Safe Mode with Networking' and hit enter. Hayaan mag load windows then check if if you ma access internet - try mo google site . pag ok na exit kana safe mo by just restarting.
4) mag try ka iba browser to see if baka yung existing gamit mo may issue na infect na malware/trojan.. e.g try ka firefox .. or chrome (dont worry free lang mga to)
5) marami pang pwede i try... depende sa result ng isolation mo..