Approx. 24 hrs. ago my three browsers became extremely slow on both my office and home networks - no other machine on either network behaves similarly. Recent developement - on many sites the page only partially loads and refresh fails to progress past the initial partial load. At home, where none is required, proxy settings set to No Proxy for all browsers, including IE. Another oddity - many links now require double-click to activate. I have disabled all add-ons. Trend Micro and Malwarebytes scans come back clean. Machine is ASUS G74SX, i7, 8GB RAM, Windows 7 Ultimate, SP1.