This question is not a duplicate of:  There is no purple screen nor black screen and the problem comes out while some loading text is printed.  The error happens before the GUI has loaded. It happens during the loading while some loading texts are shown.  Hardware: &nbsp;&nbsp;standard preassembled motherboard &nbsp;&nbsp;Intel Core i7 3770 &nbsp;&nbsp;Nvidia GTX 970 &nbsp;&nbsp;standard Western Digital hard drive       Photo of the screen while freezing on loading text
I am trying to boot Ubuntu on my computer.  When I boot Ubuntu, it boots to a black screen.  How can I fix this? Table of Contents:
I had Ubuntu 12.04 Beta installed on my computer. When 12.04 was finally released, I made a bootable USB Flash Drive using Startup Disk Creator.  Then I decided to check if this drive works properly and to reinstall the system on my desktop. I must add, my desktop behaves a bit strange when it comes to bootable USB's, it recognizes them as HDD.  In BIOS I changed priority of boot so USB Flash Drive (recognized as HDD) was first. Successfully booted, I installed Ubuntu. Everything worked fine, but...  Now I cannot boot from my real HDD. Every time I want to boot, I put the USB Flash Drive into my computer, boot, safely remove it and everything works.  What do I need to do to repair boot? Is there word for this, other than know-it-all? Just wondering, if there's a word for:  One who makes it appear as if they're an expert on a subject while there are also signals (subtly or blatantly noticeable) that this person doesn't know very much on the subject or at least as much as they're acting like they do on the subject; pretending to have much knowledge on a subject matter.  I found pedantic but I don't suppose it's the right word. Consider the following file:  \documentclass{beamer}  \setbeamercolor{title}{bg=red} \setbeamercolor{author}{bg=yellow} \setbeamercolor{date}{bg=} \setbeamercolor{institute}{fg=red,bg=green}  \title{TitelTitelTitel} \author{meiermueller} \institute{Institute} \date{lalala}  \begin{document}  \usebackgroundtemplate{\color{blue}\rule{20cm}{15cm}}    \begin{frame}    \titlepage  \end{frame} \end{document}   On one of my computers (using MiKTeX 2.9 and beamer 2015/01/05 3.36), the result is the following:    Note how, in particular, the date box has a transparent background  On my other computer, I installed a new MiKTeX version (2.9.6800), including beamer 2018/09/02 v3.52, and get this:    Here, the date field has a white background, and I cannot seem to get it to be transparent.   Apparently, the difference has some relation to the beamer version, or maybe some other change in the new MiKTeX version.  But what ist the reason, and how do I get transparent backgrounds? Can we search posts by number of comments? What exactly did mv /tmp/folder/* /* do to my filesystem? It's hard to search for special characters on google, which is why I'm posting this here.  I recently ran (as root) a mv /tmp/folder/* /* when I meant to run mv /tmp/folder/* ./ Big mistake!  Things broke! A lot of files got mixed up and placed into strange places, none of the normal unix commands worked (ls, dir, cat, etc) and once you logged off, you couldn't ssh back in -- it would give you a prompt, but not accept the old passwords.  Running ls /* shows me that it performs ls on every directory in /. If I tried to draw a parallel, then mv should have simply moved (or copied?) the files to every directory in /. Instead, really weird things happened, and I was just curious what exactly was going on.  More info: The files in /tmp/folder had been transferred from a windows machine, and had been named file (#).txt, where (#) is a number up to two digits, with a space between file and the parenthesis. There were ~40 of these text files. Posting and answering questions you have already found the answer to Understanding d-separation theory in causal Bayesian networks I am trying to understand the d-Separation logic in Causal Bayesian Networks. I know how the algorithm works, but I don't exactly understand why the "flow of information" works as stated in the algorithm.    For example in the graph above, lets think that we are only given X and no other variable has been observed. Then according to the rules of d-separation, the information flow from X to D:   X influences A, which is $P(A)\neq P(A|X)$. This is OK, since A causes X and if we know about the effect X, this affects our belief about the cause A. Information flows. X influences B,which is $P(B)\neq P(B|X)$. This is OK, since A has been changed by our knowledge about X, the change at A can influence our beliefs about its cause, B, as well. X influences C,which is $P(C)\neq P(C|X)$. This is OK because we know that B is biased by our knowledge about its indirect effect, X, and since B is biased by X, this will influence B's all direct and indirect effects. C is a direct effect of B and it is influenced by our knowledge about X.   Well, up to this point, everything is OK for me since the flow of the information occurs according to intuitive cause-effect relationships. But I don't get the special behavior of so called "V-structures" or "Colliders" in this scheme. According to the d-Separation theory, B and D are the common causes of C in the graph above and it says that if we did not observe C or any of its descendants, the flow information from X is blocked at C. Well, OK, but my question is why?  From the three steps above, started from X, we saw that C is influenced by our knowledge about X and the information flow occurred according to the cause-effect relationship. The d-Separation theory says that we cannot go from C to D since C is not observed. But I think that since we know that C is biased and D is a cause of C, D should be affected as well while the theory says the opposite. I am clearly missing something in my thinking pattern but can't see what it is.  So I need an explanation of why the flow of information blocked at C, if C is not observed. SD card not showing files when connected to pc What happened after the Ring was dropped into Mount Doom? In the Peter Jackson movie, once the One Ring is thrown into the volcano in Mount Doom, why does the mountain and tower collapse, and the ground disappears everywhere where the orcs are standing but not where the humans are? Where are all the orcs running to, what do they do next? Render looks darker than Look Dev mode I have been texture painting in look dev mode. But when i try to render it, everything looks very dark. I have 3 sun lights in my scene, ambient turned on in Eevee settings. What am i missing? I really like the look of my scene in Look Dev mode, how can i achieve the same look when my scene is rendered too? I am trying to balance underbraces in the equation below, how can I ensure that both underbraces at the same depth?  \begin{equation} y = \underbrace{ \left [ x^2 + r^2 (a^2+\frac{a^{0.3}}{b}) \right]}_\text{growth rate} \times  \underbrace{ C_0}_\text{initial} \end{equation} How to kill applications I have been playing around with Ubuntu installing new themes and and docks. Sometimes during the installation, whole screen just hangs. What is the best way in Ubuntu to Kill a process/application? Anything similar to Ctrl + Alt + Del of windows? C++ templates that accept only certain types $2\cos^2x=1+\sin x$.  Determine the exact values of $x$ such that $0 \leq x \leq 2\pi$.    I am experiencing problems with factoring this question.  First I started by getting everything on to the left side so: $2\cos^2x-\sin x-1=0$.  Then seeing as there are two trig variable here ($\cos$ and $\sin$), I used the pythagorean identity and replaced $2\cos^2x$ with $1-2\sin^2x$ to make it into a one variable question: $1-1-2\sin^2x-\sin x-1=0$.   By collecting like terms it then becomes $-\sin^2x-\sin x=0$.  Now you could factor these with $0$ and $-1$, but then it creates uneven brackets so this musn't work.  I don't think the quadratic formula is necessary, but I am wondering if this could be treated as a difference of squares question.    If you replace the $\sin x$ and make the question into $-x^2-x=0$ it is a little easier to look at, however I am not sure if this is the right approach.  If someone could please clarify my answer, that would be appreciated! Rerender funnel highcharts with new data Bump and color data in a single brush? Is there any way to paint onto a bump map and diffuse map at the same time, so that the strokes match up? Like a multi-layer brush that uses a greyscale texture for the bump layer and a color texture for the diffuse color?  Here's a rough sculpt to demonstrate what I'm imagining:    The GIF above shows how such a brush could be made. The black and white height map would be the displacement brush, transferring its greyscale data to the bump map texture and the green one would transfer its color data to the diffuse map texture.  The resulting brush images:      Making the brush is one thing, but is it possible to use such a brush? Why would spacetime curvature cause gravity? How to run scripts on start up? How can I run scripts automatically when Ubuntu starts up so I don't have to run them manually after startup? Prove that $\frac d {dx} x^n=nx^{n-1}$ for all $n \in \mathbb R$.   I saw some proof of $\frac d {dx} x^n=nx^{n-1}$ using binomial theorem, which is only available for $n \in\mathbb N$. Do anyone have the proof of $\frac d {dx} x^n=nx^{n-1}$ for all real $n$? Thank you. For each of the following, give an example of a sequence of functions $f_n$ that converges to f  A. uniformly but not in the mean square sense.  B. in the mean square sense but pointwise nowhere.  I know that for part A the domain of the function cannot be bounded but other then that I'm not sure how to go about the problem