Hi everyone, First of all I'm sorry if this has been treated before, I couldn't find any recent post on the subject and figured some things may have changed. Since updating from 10.9 to 10.9.1 my Macbook Pro (13", medio 2010) is so extremely slow that it's impossible to do anything. Just loading the desktop and the previews of photos and documents on it takes 1 hr or so. Any general help for this problem would be great; I don't think it's a hardware issue as Windows on bootcamp seems to work fine (even though I let the mac fall on the ground just before the update). As suggested by others, I already reset the NVRAM and SMC and went to safe mode to control/repair the hard disk - to no avail. Then, I created another user account, and while there's still considerable lag (indicating the problem's still there), the overall performance is better. This would mean, imo, that a) I need to resort to a more thorough method to fix the problem, ie. copying/erasing the hard disk and removing everything back, and b) that I need to delete and recreate my user account to get rid of the user files/preferences that are obviously causing the extreme slowness (right?). My question thus relates to how to do that, keeping in mind that I'm not much of a mac geek. On a side note, I can't install some firmware update from the apple store: after downloading and installing, the mac gives a beep sound when it restarts, followed by a black screen (although it's still running). But this may be a completely unrelated matter. Thank you in advance for any advice or help!