A few weeks ago, IE7 suddenly slowed down on my main PC. Each time I'd start it up, IE7 would take several seconds to get past the "Connecting..." message, meanwhile leaving me staring at a blank window. Once I got to the first screen, performance improved, but occasionally clicking a link would produce a 404 error and I'd have to click Refresh to display the page.

At first time I didn't have time to fool with it, especially since I was spending most days on the road with my laptop, where IE7 was still running normally. But when I sat down at my PC Monday morning, launched IE7, and waited 10 seconds or so for the page to appear, I really got steamed.

After verifying that certain features such as the phishing filter were turned off, I began disabling add-ons one at a time. Sure enough, the culprit came to light: The Windows Live Sign-In Helper. Disabling it using the Tools->Manage Add-Ons menu got IE7 running normally again.

I don't even know when that add-on was installed, but it sure is frustrating when an add-on from the same company that produces the browser makes the browser run in slow motion. If I was the IE team, I'd be ticked.