I installed Kali Linux as dual boot and it works well, i.e. I had both Windows 10 and Kali Linux and before loading the operating system, the bootloader asks for the operating system to load.  Now, 5 days ago, I reinstalled Windows 10 and formatted the disk which contains Windows 10. I successfully installed it and it's working well.   The problem is that now, it no longer asks about which operating system I want to choose. It systematically loads Windows 10, so I no longer have a working dual boot.  One important thing: I installed Kali Linux on a separate drive. I made another drive (taking space from "drive D" and not from the Windows drive which is "drive C").  That drive which I made only for Kali Linux didn't get formatted during the reinstallation of Windows 10.  sorry about I give you pain to read the such a long article but I have to clear the overall scenario
My system was configured to dual boot Ubuntu 12.04.1 LTS and Windows 7. Today I got my hands on the MSDN release of Windows 8 and I installed it over my Windows 7. Now the computer just boots to Windows 8 directly without loading the GRUB screen.  So I followed the steps as suggested in: . Running this command:      ls -l /dev/disk/by-label/   gives the following output:      total 0     lrwxrwxrwx 1 root root 10 Sep 11 07:51 Entertainment -&gt; ../../sda2     lrwxrwxrwx 1 root root 10 Sep 11 02:45 PENDRIVE -&gt; ../../sdb1   Also fdisk -l command gives this as the output:      Disk /dev/sda: 320.1 GB, 320072933376 bytes     255 heads, 63 sectors/track, 38913 cylinders, total 625142448 sectors     Units = sectors of 1 * 512 = 512 bytes     Sector size (logical/physical): 512 bytes / 512 bytes     I/O size (minimum/optimal): 512 bytes / 512 bytes     Disk identifier: 0x1246aa23         Device Boot      Start         End      Blocks   Id  System     /dev/sda1   *        2048   319582199   159790076    7  HPFS/NTFS/exFAT     /dev/sda2       319582208   602906623   141662208    7  HPFS/NTFS/exFAT     /dev/sda3       602908672   625135615    11113472   83  Linux      Disk /dev/sdb: 1939 MB, 1939865600 bytes     64 heads, 63 sectors/track, 939 cylinders, total 3788800 sectors     Units = sectors of 1 * 512 = 512 bytes     Sector size (logical/physical): 512 bytes / 512 bytes     I/O size (minimum/optimal): 512 bytes / 512 bytes     Disk identifier: 0xc3072e18         Device Boot      Start         End      Blocks   Id  System     /dev/sdb1   *        2248     3788799     1893276    c  W95 FAT32 (LBA)   So I assume that I have to run this: sudo grub-install /dev/sda3 to get GRUB up and running. But I am getting this error:      /usr/sbin/grub-probe: error: cannot find a device for /boot/grub (is /dev mounted?).   Can anyone please guide me in the right direction? The current Ubuntu installation is far too customized to my needs to lose it to a boot manager issue! Any help is much appreciated!
How do I declare and initialize an array in Java? Schengen Business visa without a business invitation letter Shell Type:  &gt;echo $SHELL /bin/ksh   Cronjob :   15 * * * * /bin/ksh /wls_domains/resMGT/logs/bea/wlr3queuetransaction.sh &gt; /wls_domains/resMGT/logs/bea/data/script.log  The script is as below:  ##log files and lookup file "wlr3queue.txt" are in the same path of the script ##/wls_domains/resMGT/logs/bea/wlr3queuetransaction.sh  Script :  #!/bin/ksh  dt=`date +%Y-%m-%d` xy=`date|awk '{print $4}'|awk -F":" '{print $1}'` yz=`expr $xy - 1` if [ $yz -le 9 ] then yz=0$yz fi  if [ $xy -gt 0 ] then  for i in `cat wlr3queue.txt` do  sum=0  count=`gzgrep -i "$dt" admin_resMGT_access.log* | grep "$yz:[0-5][0-9]" | grep "$i" | wc -l`  if [ $count -gt 0 ] then name=`echo $i | cut -d'/' -f3`  gzgrep -i "$dt" admin_resMGT_access.log* | grep "$yz:[0-5][0-9]" | grep "$i" | awk '{print $8}' &gt; consumed_time.txt  for j in `cat consumed_time.txt` do j_ms=`echo "$j * 1000" | bc` echo $j_ms &gt;&gt; consumed_ms_time.txt done  for k in `cat consumed_ms_time.txt` do sum=`echo "$sum + $k" | bc` done  avg=`echo "scale=2; ($sum/$count) "| bc`  min=`cat consumed_ms_time.txt | sort -n | head -1`  max=`cat consumed_ms_time.txt | sort -n | tail -1`  else  avg=0  min=0  max=0  fi ( echo $yz","$count","$avg","$min","$max )&gt;&gt;/wls_domains/resMGT/logs/bea/data/$name$dt.csv   rm -f consumed_ms_time.txt  done  else  echo "script won't execute at this hour" &gt; temp.txt  fi   I have executed the following commands and the script ran successfully.  ./wlr3queuetransaction.sh sh -x wlr3queuetransaction.sh /bin/ksh /wls_domains/resMGT/logs/bea/wlr3queuetransaction.sh  /bin/ksh/ wlr3queuetransaction.sh.   How to debug? What to do? I want to fill a part of a picture with more or less evenly and randomly distributed circles which should not overlap. It would be okay if circles are only partly inside the shape.  The density should be like what you see on this page  with values 80-100. (But I do not need so many circles, 30 should be enough, I could repeat the pattern).   I cannot use a grid and "wobble" the circles a bit: The circles are too large and it simply does not look randomly.   Currently I am thinking about a random attempt: Get some random point, measure its distance to existing circles, either paint or throw the point away. Try 100 times and hope that you get the right number of circles (and that it does not take too long). But perhaps someone has a better idea.   The example draws the circles simply manually:  \documentclass{article} \usepackage{tikz} \usetikzlibrary{backgrounds} \begin{document}   \begin{tikzpicture}[framed,gridded,radius=0.5cm]  \draw[red](0,0) rectangle (5,5);   \draw (1,1) circle;   \draw (2.3,1.1) circle ;   \draw (4.5,0.8) circle ;   \draw (5.1,1.8) circle ;   \draw (0.4,3.3) circle ;   \draw (2.1,2.8) circle ;   \draw (3.8,3.5) circle ;   \draw (4.8,4.2) circle ;   \draw (0.8,4.9) circle ;   \draw (2.1,4.1) circle ;   \draw (3.8,2.0) circle ;   \draw (3.5,0.6) circle ;   \draw (3.0,5.0) circle ;      \draw (4.1,5.1) circle ;             \draw (0.9,2.1) circle ;  \end{tikzpicture}  \end{document} Convergence of $\int_0^\infty $sin$ (x^p) dx$ Can Windows Virtual PC run a 64-bit OS? How can I get a reference to a method? Show that $\left|\frac{\alpha - \beta}{1-\bar{\alpha}\beta}\right| < 1$ when $|\alpha|,|\beta| < 1$ Inequality with complex numbers Consider the following problem.  Fix $n \in \mathbb N$. Prove that for every set of complex numbers $\{z_i\}_{1\le i \le n}$, there is a subset $J\subset \{1,\dots , n\}$ such that   $$\left|\sum_{j\in J} z_j\right|\ge \frac{1}{4\sqrt 2} \sum_{k=1}^n |z_k|.$$  I believe I proven have a stronger statement. Is this proof correct, and if so, what is the optimal constant?  My proof. Consider all the $z_i$ with positive real part. Call the real part of the sum of these numbers $X^+$. In a similar way, form $X^-$, $Y^+$, and $Y^-$. Without loss of generality, let $X^+$ have the greatest magnitude of these.  Note that because $|\operatorname{Re}(z)|+|\operatorname{Im}(z)|\ge |z|$, we have  $$ \left(\sum_{k=1}^n  |\operatorname{Re}(z_k)|+|\operatorname{Im}(z_k)| \right) \ge \sum_{k=1}^n |z_k|.$$  But note that $\sum \limits_{k=1}^n  |\operatorname{Re}(z_k)|+|\operatorname{Im}(z_k)| = X^+ + |X^-|+ Y^+ +|Y^-|$, so we have  $$ 4X^+ \ge \sum_{k=1}^n |z_k|.$$ By choosing $J$ to be the set of complex number with positive real part, this proves a stronger statement, because the factor of $1/\sqrt 2$ isn't needed. I wanted to tweet something on the lines of "Stack&nbsp;Overflow is awesome". When I do this kind of stuff, I usually use a username (for example: ) or a hashtag ()  I found , but it seems it is from someone unrelated with Stack&nbsp;Overflow.  Is there a Twitter account I can reference, or should I use a hash-tag? Should I just point to the site?  Thanks!  (Notice: I've seen lots of questions regarding Twitter and Stack&nbsp;Overflow, but those are mostly about integration/login with Twitter for the users accounts; I'm just asking for a single account for Stack&nbsp;Overflow; probably for announcements and PR, which is different) Notepad doesn't open files created by Gedit? Excel automatic hyperlinks How does Delta baryon decay conserve angular momentum? I'm a chemist so bear with me:  I understand the  $\Delta^{+}$ and $\Delta^{0}$ to be in some sense spin (and isospin) quartet states of the proton and neutron. These can decay straight to a proton or neutron through emission of a pion, which is spin-0.  I've been puzzling about the mechanism by which this decay conserves spin. I note via Wikipedia that  into either a lepton pair or a photon pair, for which it's easy to show spin is conserved, however pion production seems to induce a loss of $J=1$.  This seems to suggest momenta of:  $\Delta^{+} (J=\frac{3}{2}) \rightarrow{} p^{+} (J=\frac{1}{2}) + \pi^{0} (J=0)$  Am I missing a boson? Is my understanding of spin flawed? I assume that if this decay exists, similar things turn up everywhere else. How does the Wizard spellbook work? How do I determine what spells are in my spellbook when creating a character? Do I simply have a spellbook with all Pathfinder spells? Or if I'm creating a level 6 wizard, do I start knowing all level 6 spells, and then have to learn the rest as I play the game? Touching the front wheel with my foot when turning What is the best way to initialize a private, static data member in C++?  I tried this in my header file, but it gives me weird linker errors:  class foo {     private:         static int i; };  int foo::i = 0;   I'm guessing this is because I can't initialize a private member from outside the class.  So what's the best way to do this? using the \lstlistoflistings always named as Contents in table of contents.  I did look into   and  but the solutions there did not work.  Example: (my complete preamble)  \documentclass[11pt, oneside]{Thesis}  \usepackage{tikz} \usepackage{pgfplots} \usepackage{pgfplots,filecontents} \usepackage{caption} \usepackage{subcaption} \usepackage{booktabs,colortbl} \usepackage{graphicx} \usepackage{rotating} \usepackage{listings} \usepackage{color} \usepackage{comment} \usepackage[official]{eurosym} \usepackage{colortbl} \usepackage{algorithm}  \usepackage{algpseudocode} \usepackage{indentfirst} \usepackage{latexsym} \usepackage{titlesec} \usepackage[square, numbers, comma, sort&amp;compress]{natbib}   \hypersetup{urlcolor=blue, colorlinks=true}  \renewcommand{\lstlistlistingname}{List of Code}   \begin{document}  \tableofcontents \lstlistoflistings \lstinputlisting[language=python,firstline=1,lastline=68,caption=some caption here., label=code:getbb]{Code/getBoundingBox.py} \end{document}   The renew command changes the header in the page but not in the table of contents. Any ideas?  EDIT x2:  Managed to get the naming correct by editing this in the Thesis.cls   }  \renewcommand\lstlistoflistings{  \btypeout{List of Listings}  \addtotoc{List of Listings}  \begin{spacing}{1}{ \setlength{\parskip}{1pt} \if@twocolumn   \@restonecoltrue\onecolumn \else   \@restonecolfalse \fi \chapter*{\lstlistlistingname   \@mkboth{       \MakeUppercase\lstlistlistingname}{\MakeUppercase\lstlistlistingname}} \@starttoc{lot} \if@restonecol\twocolumn\fi \cleardoublepage  }\end{spacing}   Now the name appears correctly in the TOC but the Listings do no show in the Listings page, its just empty..  A MWE can be found here: Is abstract algebra (mostly?) restricted to $2$-ary operators? This may be due to my own pure ignorance but it's my experience that all abstract algebra I've been introduced to, both in actual courses and in self-studies only exclusively deals with algebraic objects consisting of a set together with one or more binary operators defined on that set, perhaps over some other algebraic structure. Not counting categories here, just "low-level"-ish stuff.  I'm an undergraduate so my knowledge is of course very limited but I can't help to wonder why I never stumble upon algebraic structures with $n$-ary operators? Is there a good reason for this, something along the lines of $n$-ary operators behave "badly" when $n&gt;2$ or is it just my ignorance because I'm a beginner in the field? Using Windows 10 in a virtual machine. Can it be done? I am currently running 8.1. I'd like to try out Windows 10 and if I like it upgrade. If not, I'll keep running as I am.   I've never used a virtual machine before: can Window 10 be used from a virtual machine as a "sandbox", and if so how? invalid conversion from ‘const char*’ to ‘char’