BleepingComputer.com: Internet Explorer cannot display the web page

My IE has not been working for several months now. My primary web browser is FireFox (awesome!). But I would like to get IE up and running again.

IE opens fine and I'm connected to the internet but I get the dreaded

"cannot display web page" message.
Most likely causes:
You are not connected to the Internet.
The website is encountering problems.
There might be a typing error in the address.

blah,blah,blah...

I have scanned for viruses, malware, etc. System is clean.

I have run "diagnose connection problems" in IE and it can't find anything wrong.

I have "reset internet explorer settings" but it still doesn't work.

I have updated IE7 to IE8 thinking that might fix it, but it didn't.

Last fall, I did some PC cleaning/maintenance to get things running smoother/faster again. I disabled some of my start up items using "system configuration utility". Everything else worked fine after that, but some time later IE stopped working so I don't know if it's connected to tweaking the start up items.

I'm running XP Home, SP2.

Any ideas?