My friend has a 2011 iMac from his Dad, we play a computer game which has had an update which now means his old OS wouldn't run it, it needs at least Mountain Lion, so after lots of research he took the plunge and bought Mountain Lion from the Mac Store for £20... however once he received the email with the download link and pressed it, it asked for a password... however the login account does not have a password and his Dad does not know what the password could be...  Is there a way to download this new OS system which we have paid for without the password?
I recently received an old iMac secondhand.  I have no way to reach the original owner. I am trying to upgrade the OS software, but the prompts demand the administrator's name (which is auto-filled) and password (which I do not have).  I understand why these security features are in place, but is there any way in the world for me to access Admin. privileges without the password?
Comments are useful. Many, many posts need some small amount of meta discussion, and comments fulfill this need.   Comments are also noisy and distracting. Occasionally, someone will post an insightful and informative comment that complements the post its attached to... But more often, they're tangential, quickly irrelevant and in the way: stale comments show up first, making newer comments less visible.  The guidance here for a long time has been that comments are transient, . And yet, some do hang around for months or years because .   So let's fix that.   I propose that all comments older than 7 days be hidden by default unless the comment has been up-voted in the past 30 days. Hidden comments should be indicated by a note below the post ("add / show 3 more comments") and made visible to anyone who cares to click it.   This doesn't destroy anything, but it would get it out of the way of most readers - and hopefully encourage folks to edit it into the actual answers as a result.  Note: I previously suggested this . Other  have been . However, I'm not suggesting that comments be automatically deleted, and they should be hidden based purely on the age / activity of the comment itself, not of the post to which they're attached. On the nilpotence of the matrix $AB-BA$ I am writing a small KOMA-Script scrartcl document with multiple sections. In the table of contents, LaTeX fills the current line with dots between the end of the section name and the page number. Is there any way to customize this behavior? I would like to reduce the space between the single dots (i.e. use more dots in the same space). Given a file L with one non-negative integer per line and text file F, what would be a fast way to keep only those lines in F, whose line number appears in file L?  Example:  $ cat L.txt 1 3  $ cat F.txt Hello World Hallo Welt Hola mundo  $ command-in-question -x L.txt F.txt Hello World Hola mundo   I'm looking for a command that can handle a file L with 500 million or more entries; file L is sorted numerically.  Note: I'm halfway through an implementation for a command-in-question but I just wondered, whether one might be able to use some Unix tools here as well.    Update: Thank for all the answers, I learned a lot today! I would like to accept more one answer, but that's not possible. DropDown list onchange event and AJAX in MVC Why doesn't "System.out.println" work in Android? Are $T\mathbb{S}^2$ and $\mathbb{S}^2 \times \mathbb{R}^2$ different? I have seen the claim that $T\mathbb{S}^2$ and $\mathbb{S}^2 \times \mathbb{R}^2$ are not diffeomorphic, but I have only ever seen the proof that they are not isomorphic as vector bundles (which is a cute application of the hairy ball theorem). How would I prove that they are indeed not diffeomorphic (or better, not homeomorphic)? What's the difference between these two sentences? And which one's grammatically correct? Prove that $a_{n}=0$ for all $n$, if $\sum a_{kn}=0$ for all $k\geq 1$ Let $S=\{\frac{m}{2^n}| n\in\mathbb{N}, m\in\mathbb{Z}\}$, is  $S$ a dense set on $\mathbb{R}$? Ignore citations in captions in list of figures when numbering Hide some fields in the NewForm.aspx for a custom list I have 5 columns in the custom list. Out of which only 3 have to displayed in the NewForm.aspx page.  All of the 5 columns have to be displayed on the EditForm.aspx page. While googling, I have come across the following  :  When I implemented the code that was given on this page, I get an error which says that parentNode is not found. Please guide me how can I implement this requirement.  Any other alternatives other than this are also appreciated. As you know, we can enable the spell checker on single line text boxes in the following way:    We have to enable it every time for checking words.  How can we enable it forever, so it doesn't need to be enabled each time? How to parse a query string into a NameValueCollection in .NET I would like to parse a string such as p1=6&amp;p2=7&amp;p3=8 into a NameValueCollection.  What is the most elegant way of doing this when you don't have access to the Page.Request object? Find remainder of division of $x^3$ by $x^2-x+1$ I am stuck at my exam practice here.      The remainder of the division of $x^3$ by $x^2-x+1$ is ..... and that of $x^{2007}$ by $x^2-x+1$ is .....   I tried the polynomial remainder theorem but I am not sure if I did it correctly.  By factor theorem definition, provided by ,     the remainder of the division of a polynomial $f(x)$ by a linear polynomial  $x-r$ is equal to $f(r)$.   So I attempted to find $r$ by factorizing $x^2-x+1$ first but I got the complex form $x=\frac{1\pm\sqrt{3}i}{2}=r$.   $f(r)$ is then $(\frac{1+\sqrt{3}i}{2})^3$ or $(\frac{1-\sqrt{3}i}{2})^3$ which do not sound right.  However, the answer key provided is $-1$ for the first question and also $-1$ for the second one. Please help. If $\gcd(a,b)=1$ and $a$ and $b$ divide $c$, then so does $ab$ Do you need to take the Hide action when you are Invisible, make no noise and leave no traces? The Situation: Lets say you are under the effect of Invisibility.  An invisible creature is impossible to see without the aid of magic or a special sense. For the purpose of hiding, the creature is heavily obscured. The creature's location can be detected by any noise it makes or any tracks it leaves.  And you are wearing the Boots of Elvenkind  While you wear these boots, your steps make no sound, regardless of the surface you are moving across. You also have advantage on Dexterity (Stealth) checks that rely on moving silently.  Now your groups ranger or druid casts Pass Without Trace on you.  [...] can’t be tracked except by magical means. A creature that receives this bonus leaves behind no tracks or other traces of its passage.  My Question(s): I know that when you are Invisible and you did not hide, you are still detectable because of the noise and the track you leave behind. But the Boots of Elvenkind and Pass Without Trace take care of that. So:  Are you still required to take the hide action in this situation if you don't want enemies to know your location/presence? If so, why? What gives away your location? If not and you are under the effect of greater Invisibility do you get the benefits of &quot;Unseen Attackers and Targets&quot; for every attack you make when you move between attacks? (You would give away your location, but are not detectable, so completely hidden again when you move) I need to remove every line that has a value of 2 or less in the 8th field (column).   My data looks like this:  12-31   Airport 189 379 41  49.70946503 -124.91377258   2   2880    30.8 01-01   AlberniElementary   165 331 16  49.26100922 -124.80662537   4   5760    26.1 01-09   BamfieldMarine  161 323 23  48.83490372 -125.13572693   2   2875    27.4 01-10   BamfieldMarine  161 323 23  48.83490372 -125.13572693   3   3068    38.6   I understand that using awk I can strip off the values desired and print them to another file, and I understand that sed would edit the current file. In either case, I need to retain the original file.   Note: Please provide thorough explanations with your solutions. It is not suffice to just write the command, please annotate suggestions.   Further note: The data has a header line, so most likely solution will need to      awk 'FNR >1'   I suppose? How do I deal with a compromised server? This is a  about Server Security - Responding to Breach Events (Hacking)   See Also:                  Canonical Version I suspect that one or more of my servers is compromised by a hacker, virus, or other mechanism:   What are my first steps? When I arrive on site should I disconnect the server, preserve "evidence", are there other initial considerations? How do I go about getting services back online? How do I prevent the same thing from happening immediately again? Are there best practices or methodologies for learning from this incident? If I wanted to put a Incident Response Plan together, where would I start? Should this be part of my Disaster Recovery or Business Continuity Planning?   Original Version       2011.01.02 - I'm on my way into work at 9.30 p.m. on a Sunday because our server has been compromised somehow and was resulting in a    attack on our provider. The servers access to the Internet   has been shut down which means over 5-600 of our clients sites are now   down. Now this could be an FTP hack, or some weakness in code   somewhere. I'm not sure till I get there.      How can I track this down quickly? We're in for a whole lot of   litigation if I don't get the server back up ASAP. Any help is   appreciated. We are running Open SUSE 11.0.            2011.01.03 - Thanks to everyone for your help. Luckily I WASN'T the only person responsible for this server, just the nearest. We managed   to resolve this problem, although it may not apply to many others in a   different situation. I'll detail what we did.      We unplugged the server from the net. It was performing (attempting to   perform) a Denial Of Service attack on another server in Indonesia,   and the guilty party was also based there.      We firstly tried to identify where on the server this was coming from,   considering we have over 500 sites on the server, we expected to be   moonlighting for some time. However, with SSH access still, we ran a   command to find all files edited or created in the time the attacks   started. Luckily, the offending file was created over the winter   holidays which meant that not many other files were created on the   server at that time.      We were then able to identify the offending file which was inside the   uploaded images folder within a  website.      After a short cigarette break we concluded that, due to the files   location, it must have been uploaded via a file upload facility that   was inadequetly secured. After some googling, we found that there was   a security vulnerability that allowed files to be uploaded, within the   ZenCart admin panel, for a picture for a record company. (The section   that it never really even used), posting this form just uploaded any   file, it did not check the extension of the file, and didn't even   check to see if the user was logged in.      This meant that any files could be uploaded, including a PHP file for   the attack. We secured the vulnerability with ZenCart on the infected   site, and removed the offending files.      The job was done, and I was home for 2 a.m.            The Moral   - Always apply security patches for ZenCart, or any other CMS system for that matter. As when security updates are released, the whole   world is made aware of the vulnerability.   - Always do backups, and backup your backups.   - Employ or arrange for someone that will be there in times like these. To prevent anyone from relying on a panicy post on Server   Fault. Don't count non-printing characters, HTML comments or other content not displayed toward minimum character requirements