I have two comp that I have downloaded Ubuntu 16.04. One is doing well. I have used windows since my first comp so I am going by "hunt and peck" trying to learn the ropes. First comp is going well but second is ?? refusing my password.  I have two Pass words that I have used since day one in the 1990's. My comp won't accept either. When I try to change password my system wants me to sign-in to auth the change??? What would anyone suggest? (I am not comp literate. 20 years plus on windows has not prepared me for this.)  I hate windows with a passion, I refuse to go to Mac. Ubuntu seemed like the obvious answer for me.
how can I reset a lost administrative password ,considering that Ubuntu and windows7 are both installed on the computer , considering also that "Boot up the machine,and after the BIOS screen, hold down the left Shift key." didn't logged me to any thing, just continue the loading of the system as normal??
Cannot suggest retag-only edit because "edits must be at least 6 characters" I was trying to suggest a retag of  on Seasoned Advice, but the system won't let me; I get the familiar message     Edits must be at least 6 characters; is there something else to improve in this post?   In general, that's not true for retagging; if you don't change the question body at all, it should work. I suspect the logic checking the edit is thrown off guard because of the title warning:     The question you're asking appears subjective and is likely to be closed       I found , but I cannot find any evidence (in SEDE) for invisible characters being present in the question's source. Also, that's supposed to be . Is there a way to have Cycles skip rendering alpha? If I wanted to create an animation, each frame would have several seconds of rendering a completely transparent part, which adds up obviously. Is there a way to eliminate this waste of time? Condition for a tensor to be decomposable When does the placement of a resistor matter? I've been a programmer for years but am very new to electronic engineering. So far I see people saying it doesn't matter where a resistor goes in your LED circuit as long as it is present, but it sounds like that's the nature of the basic LED circuit.  When does the placement of a resistor start to become important? Why is     $$\lim_{n \to \infty} \frac{2^n}{n!}=0\text{ ?}$$   Can we generalize it to any exponent $x \in \Bbb R$? This is to say, is     $$\lim_{n \to \infty} \frac{x^n}{n!}=0\text{ ?}$$     This is being repurposed in an effort to cut down on duplicates, see here: Coping with  duplicate questions.  and here: . Exec format error of gcc-compiled Hello World c++ On AWS Ubuntu Server, I wrote C++ Hello, World program:  #include &lt;iostream&gt; using namespace std;  int main(){         cout&lt;&lt;"Hello, World!"&lt;&lt;endl;         return 0; }   And compiled it:  ubuntu@ip-xxxxx:~/dev/c++$ g++ -c ./test.cc -o out ubuntu@ip-xxxxx:~/dev/c++$ chmod a+x out ubuntu@ip-xxxxx:~/dev/c++$ ./out -bash: ./out: cannot execute binary file: Exec format error ubuntu@ip-xxxxx:~/dev/c++$ file ./out ./out: ELF 64-bit LSB  relocatable, x86-64, version 1 (SYSV), not stripped ubuntu@ip-xxxxx:~/dev/c++$ uname -a Linux ip-xxxxx 3.13.0-48-generic #80-Ubuntu SMP Thu Mar 12 11:16:15 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux ubuntu@ip-xxxxx:~/dev/c++$ gcc --version gcc (Ubuntu 4.8.4-2ubuntu1~14.04) 4.8.4   It seems that architecture x86-64 is the same each other. What is the problem here? Do I have to add more C++ flags? Find the value of : $\cos x \cos 2x...\cos 999x$ given that $x=\frac {2\pi}{1999}$ Why is it better to use "#!/usr/bin/env NAME" instead of "#!/path/to/NAME" as my shebang? I notice that some scripts which I have acquired from others have the shebang #!/path/to/NAME while others (using the same tool, NAME) have the shebang #!/usr/bin/env NAME.  Both seem to work properly.  In tutorials (on Python, for example), there seems to be a suggestion that the latter shebang is better.  But, I don't quite understand why this is so.  I realize that, in order to use the latter shebang, NAME must be in the PATH whereas the first shebang does not have this restriction.  Also, it appears (to me) that the first would be the better shebang, since it specifies precisely where NAME is located.  So, in this case, if there are multiple versions of NAME (e.g., /usr/bin/NAME, /usr/local/bin/NAME), the first case specifies which to use.  My question is why is the first shebang preferred to the second one? Are there some good overviews of basic facts about images and inverse images of sets under functions? Should I mention my Canadian visa refusal in my UK visa application? Why are the orbits of planets in the Solar System nearly circular? Except for Mercury, the planets in the Solar System .  Is this property special to the Solar System?  :     Most exoplanets with orbital periods of 20 days or less have near-circular orbits of very low eccentricity. That is believed to be due to tidal circularization, an effect in which the gravitational interaction between two bodies gradually reduces their orbital eccentricity. By contrast, most known exoplanets with longer orbital periods have quite eccentric orbits. (As of July 2010, 55% of such exoplanets have eccentricities greater than 0.2 while 17% have eccentricities greater than 0.5.) This is not an observational selection effect, since a planet can be detected about equally well regardless of the eccentricity of its orbit. The prevalence of elliptical orbits is a major puzzle, since current theories of planetary formation strongly suggest planets should form with circular (that is, non-eccentric) orbits.   What is special about the Solar System that orbits of planets here are nearly circular, but elsewhere they are moderately or highly eccentric? How do I change which audio jacks are used for input and output? I'm using a Realtek HD audio card built-in my motherboard. The Windows driver comes with a control panel that allows me to select which back panel jacks are used for what. So for example I can make both the blue jack and green jack for output and only the red one for mic-in. (Whereas by default, the blue jack is for line in, which I never need.)  How can I do the same under Linux? If possible, please don't suggest something that involves PulseAudio or JACK; I'd like to do it the plain way, e.g. by editing ALSA configuration files, if possible. The way I understand it, my problem should have nothing to do with software servers redirecting streams, just instructing the driver to treat this jack as so and so because it's hardware supported.  Thank you very much! Behave as if it was or it were You can place the script in the head or body as you like. The   script will behave as if it was located exactly where you put the   script tag in the document.   The sentences above are taken from  (at the very bottom). I think they made a grammatical mistake here: it should be behave as if it were rather than it was. I'm not 100% sure, so want to confirm it. Is hyperref really the best way to add metadata to a TeX file? So I know one of hyperref's features is that it can add metadata to you PDFs. This is a nice feature and if you're putting stuff online, it's good to include metadata.  But is the hyperref package really the best way to do it? I mean, if you're using hyperref anyway, that's fine. But if you don't want hyperrefs in your document, it seems weird to include the package, and then turn off pretty much all its functionality. And given that hyperref is a shorthand for "package conflict nightmare", is seems insane that you should have to deal with it just for the sake of some metadata.  So I have two questions.   Is there a good reason that hyperref includes this functionality which is apparently unrelated to its primary purpose? Is there a better (smaller, less conflicty, easier...) option to include metadata in my PDFs? Why are my sauces splitting? Biometric information for a UK visitor visa for the second time I submitted my biometric information when I applied for (and successfully received) the UK visitor visa.  Now, the visa has expired and I would like to apply for it again.   Do I need to submit my biometric information again?  Will the process be the exact same as before? How long can cooked food be safely stored at room/warm temperature? Should I use the datetime or timestamp data type in MySQL? What are some good tips on how to extrude text in Adobe Illustrator? I'm bit of a newbie in Adobe Illustrator and have been learning the application by trying to follow some tutorials and recreating some cool stuff I come across on the web.   That being said, I'm having trouble replicating the effect found in the following image using the standard 'Extrude &amp; Bevel' options. I've also tried copying + pasting the text in front, back, in place and that came out even more horrendous. 'Extrude &amp; Bevel' gives me a nice approximation but nothing that pops out like in the example.   Any tips on how to fine tune my 'Extrude &amp; Bevel' settings or an entirely different method of achieving a similar effect would be very much appreciated. Thanks for your time and help!  How can I create a 3D effect on my text similar to the one in the following image, using Illustrator's Extrude and Bevel tools? Prove that, for every natural n, $\sum_{d|n} \frac{\mu(d)}{d}=\prod_{p|n}(1-\frac{1}{p})$