I found the two updates which crippled my laptop’s Windows installation. After uninstalling and re-installing lots of updates, it seems that these two updates caused the problem:
Update for Windows Vista (KB936825) This wasn’t the one. The problem was back this morning. 🙁 I’ll be checking this out later today.
– Update for Outlook 2007 (KB933493)


Re-installing them causes the same problems to occur: Outlook can’t connect to Exchange and IE7 can’t display any webpages. The weird thing is these updates were installed on my regular machine, and didn’t cause any trouble there. On our laptop, the problems act up. Weird stuff… I’ve hidden the updates on the laptop, so I think the problem will not come back.

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Update 2: OK, this is weird. I mentioned the problem returned this morning. So when I came back fom work today I removed a different update and rebooted, and the internet connection was fixed again. So, to be sure, I re-installed the update and restarted again. And now the internet connection keeps working, even after numerous restarts :S. Creepy stuff, but the connection works perfectly now. So I guess I’ll have to accept I won’t be sure what the problem was.