A friend of mine has had a weird problem - he kept being prompted to install the same XP update (KB835732). I told him to remove the update - my guess was as good as his - redownload, and reinstall it. Everything went smooth until reboot; I wasn't there, but the machine took ages to start then reported it had recovered from a "critical failure". The update warning hasn't reappeared, though.
Normal hiccup or a possible problem ?