I do not know which Windows version I have running on my laptop. How do I find this out? I need to know before telephoning my service provider.
If you have to provide some initial troubleshooting support by phone [or email], and you don't have access to the user's PC itself, what is the easiest and most foolproof question one can ask of the user to find out if the 'dumb' user is using either Windows 7 or Windows Vista?  For example: determining if the user has either Windows XP or Windows Vista/7 is easy. Just ask the user if the button at the left bottom corner is (a) either square with the word 'Start' on it, or (b) it is a round button.   But how do you determine the difference between Vista and 7?  Edit: For all the existing answers the user has to type something, and do it correctly. Sometimes even that is already hard for a computer illiterate user. My XP example just requires looking. If it exists (although I am afraid it doesn't), I think a solution that is just based on something this is visually different between Vista and 7 would stand above all others. (Which makes Dan's suggestion to turn over the box and look at the label" not so stupid). Perhaps the small 'show desktop' rectangle at the right side of the task bar (was that present in Vista)?
I was wondering if anybody knew a command that would allow me to open a Nautilus (if that's the right name for the Ubuntu graphic/window explorer) window from the command line at the current directory that the user is at.  So, if I open a command line, and type:  cd /home/myUser/some/long/path/to/a/directory   Then, I'd like to be able to issue some command:  nautilus open-sesame   And have a graphic window opened to /home/myUser/some/long/path/to/a/directory. Is this even possible? I've just installed QGIS 3.2.2 and after installation, tried to use the Plug in Manager to install the OpenLayers plugin.  But it's not in the list to install.    Any ideas? How to move my cube left or right using touch Inputs (C#) in unity I am trying to create a 3d game in unity. I have a cube in unity and I want it to move left or right on swipe . It should move to a distance till where user swipe or take their finger off of a screen. I want it to move fast or the cube should move fast on swipe and cube should flow smooth. Like in the gif there is a circle and the user use their finger to move the circle till wherever the user swipe it and it should be instant and I want my cube to move like that at a distance till where user swipe their finger and it should be instant and fast.  I don't know how to do it. Any help is appreciated! I've read a lot about PCA, including various tutorials and questions (such as , , , and ).   The geometric problem that PCA is trying to optimize is clear to me: PCA tries to find the first principal component by minimizing the reconstruction (projection) error, which simultaneously maximizes the variance of the projected data.    When I first read that, I immediately thought of something like linear regression; maybe you can solve it using gradient descent if needed.  However, then my mind was blown when I read that the optimization problem is solved by using linear algebra and finding eigenvectors and eigenvalues. I simply do not understand how this use of linear algebra comes into play.  So my question is: How can PCA turn from a geometric optimization problem to a linear algebra problem? Can someone provide an intuitive explanation?  I am not looking for an answer like  that says "When you solve the mathematical problem of PCA, it ends up being equivalent to finding the eigenvalues and eigenvectors of the covariance matrix." Please explain why eigenvectors come out to be the principal components and why the eigenvalues come out to be variance of the data projected onto them  I am a software engineer and not a mathematician, by the way.  Note: the figure above was taken and modified from . Global hotkey in console application Whenever I try to do a fluid simulation, the fluid domain remains visible.  I have tried:ctrl+a-scale, turn on/off visibility for render/viewport  Here's a video demonstrating my problem:   Here's the blend file in case I have messed up some settings:   Thank you for any help! One of the new search hints is wrong How do people at Hogwarts usually tell the time? Classes and lessons at Hogwarts are presumably scheduled at fixed times of day. The first class might start, for example at nine in the morning.  To be on time for one's lessons, it is therefore crucial to know the current time but we know that electric watches of course do not work at Hogwarts because of all the magical interference. Are there magic watches? Is there maybe a spell to tell the time?  How do people at Hogwarts usually tell the time? What determines how much experience I get from a hearthstone match in play mode? Sometimes I win handily and get a little experience, sometimes I squeak out a victory and get a lot.  How is experience earned? What do Android application permissions mean? When installing an application, the application lists permissions that it needs to perform its  functions.    I am creating this list of the the system defined permissions and a description of what they mean. It is a community wiki so if new permissions are added in the future they can be added to this list. The Equation $11^x + 13^x + 17^x =19^x  $  Has    No Real Roots Only One Real Roots Exactly Two Real Roots  More than Two Real Roots    What I have done is   The function $f(x)=11^x + 13^x + 17^x -19^x  $ is strictly increasing and being always positive it have no roots House wiring and grounding. How do you retrofit an old house and ground it? A contractor looked at our house and told me that you can't fix a house (with old wiring) that has some outlets that are not grounded.  He said that you can go on YouTube and search the internet and it will tell you that you can.  He says that the only way to properly fix and ground everything is to do a whole house rewire.  Is he correct?  If, theoretically, you have an old house that has no ground whatsoever, can you run a grounding wire from the panel to all of the outlets to fix this?  updated  We have BX/AC wiring. And also apparently we have "...old-style AC (BX) with cloth insulated wires in a paper overall wrap under the spiral armor (no bonding tape)" Courtesy of @ThreePhaseEel. "ERROR: Extra }, or forgotten \right." in align* enviroment Why do I get a "ERROR: Extra }, or forgotten \right." in the following align* environment?  \begin{align*}     \int\left[\left(\der{E_z}{y}-\der{E_y}{z}-\mu\der{\alpha}{t}\right)\alpha&amp;+\left(\der{E_x}{z}-\der{E_x}{x}-\mu\der{\beta}{t}\right)\beta\\     &amp;+\left(\der{E_y}{x}-\der{E_x}{y}-\mu\der{\gamma}{t}\right)\gamma\left.\vphantom{\left(\der{E_y}{x}}\right]d\omega=0.     \end{align*}   thanks In eevee, shadows are clipped by camera distance As shown in the gif, the shadow in eevee is clipped by the camera distance. The same is true for F12 rendering. Where are the options to improve this issue? $\mathbb R = X^2$ as a Cartesian product I wonder if it is possible to consider $\mathbb R$ as a Cartesian product $X\times X$ for some set $X$. From the point of view of the dimensionality, there are spaces with a Hausdorff dimension $1/2$ (sort of Cantor sets), but I guess there are other problems in this construction  unrelated to the dimension.  Edited: replying on the comment by Asaf. I want that for all $r\in\mathbb R$ there exists a unique representation $r=\langle x,y\rangle$ where $x\in X$ and $y\in X$. Also, what if we want to have $X$ to be a topological space and $h:X\times X\to\mathbb R$ to be a homeomorphism? I am thinking of moving my extensive eBook library to iBooks or Kindle. Has anyone done this, and what does it take?  I just don't want book libraries in multiple proprietary formats, and have to look for content across apps. When is the new ball due for all forms of cricket? Is there a standard time fixed in Test, ODI and T20 formats of Cricket, when a fielding side captain can ask for a new ball?  If the captain of the fielding side doesn't ask for a new ball, will he be forced to have it mandatorily after a certain point by the match umpires? How discontinuous can a derivative be? There is a well-known result in elementary analysis due to Darboux which says if $f$ is a differentiable function then $f'$ satisfies the intermediate value property.  To my knowledge, not many "highly" discontinuous Darboux functions are known--the only one I am aware of being the Conway base 13 function--and few (none?) of these are derivatives of differentiable functions.  In fact they generally cannot be since an application of Baire's theorem gives that the set of continuity points of the derivative is dense $G_\delta$.  Is it known how sharp that last result is?  Are there known Darboux functions which are derivatives and are discontinuous on "large" sets in some appropriate sense? I'm using soul to letterspace headings in a Hungarian document and compiling it with lualatex.  For some reason soul drops some of the accented letters at the end of a word, but not all. In the example below, only ő and ű are affected:  \documentclass{minimal} \usepackage{fontspec} \setmainfont[Ligatures = TeX]{TeX Gyre Pagella} \usepackage{soul} \begin{document} \noindent \so{áll llá ÁLL LLÁ}\\ \so{íll llí ÍLL LLÍ}\\ \so{űll llű ŰLL LLŰ}\\ \so{őll llő ŐLL LLŐ}\\ \so{üll llü ÜLL LLÜ}\\ \so{öll llö ÖLL LLÖ}\\ \so{úll llú ÚLL LLÚ}\\ \so{óll lló ÓLL LLÓ}\\ \so{éll llé ÉLL LLÉ} \end{document} Convert a number to a string with specified length in C++