I have a laptop that had Windows 7 previously installed but now has Windows 8.1. I want to dual boot with Ubuntu 13.10. But I was curious on how to do this properly and in the case that GRUB messes up my computer just delete it and restore it to the original Windows bootloader. Also DON'T recommend EasyBCD. I don't mind using GRUB but I want to be sure I can remove Ubuntu and GRUB.
I need my pre-installed version of Windows 7 (or any other version of Windows), how could I install Ubuntu without erasing it?
Is the 2DS region locked? Will I be able to play NA games on a Japanese System? If I purchase a 2DS from Japan, will I be able to play American games on it? Books for general relativity I tried turn on in compizconfig but I does not work. Any solution or it is possible? Probability of a player winning before another Given a 7 sided dice, 2 players roll it independantly simultaneously and when a player rolls a '6' he gets a prize.  What is the probability of the first player getting a prize before the second?  So my solution is to sum over all the turns j in which player 1 could win, and make the second player lose all these turns:  $$P(A) = \sum_{i=1}^{\infty}(6/7)^{j-1}*(1/7)*(6/7)^j = 0.461$$ My question is if my solution is correct, and if so, why is the probability so low? It seems to me that either player 1 wins before the 2nd or the other way around, and the probability of them playing forever is 0, so it should be 0.5? HDD SMART interpretation - Possible impending drive failure I've just had an issue pop up related to my drives.  First things first, I was working in my case when I clumsily shifted the foot of the case off of my desk. Case shifted and hit the desk somewhat hard, but only fell an inch or two. It had been properly shut down so this may not have anything to do with the issue.  After booting up, I noticed that when playing a video from my F: Drive (Seagate), it produced a whine, almost a chirping sound coming from the hard drive bay. I think I may have heard this before the drop, but quieter.  Fearing impending failure I downloaded GSmartControl and inspected the drive information. The Seagate drive displayed a high Raw Read Error Rate, as well as a high Seek Error Rate.  I've read some of these values can be high on Seagate drives from the start. This drive is about 6 months old and the producer of the noise.  I also checked my Toshiba drive, which came with a refurbished prebuilt I bought about a year ago. It showed more normal SMART data, but displayed some concerning statistics (2 "Mechanical Start Failures" and 2 "Reported Uncorrectable Errors").  Both of the drives passed the basic SMART test, but the noise was quite alarming. It would stop as soon as a paused the video and start right up again as soon as I resumed playing.  Here is an album with 3 photos of the SMART data, the Seagate did not display statistics.  Could I please have help interpreting the SMART data, and whether this may indicate an impending failure?   Thank you for your time.   Here are images of the SMART data. Mann-Whitney U test and K-S test with unequal sample sizes How to use paging in a WFS query? I am running a GetFeature request against a WFS server which does not support to download all data at once. Can I use ogc:PropertyIsGreaterThanOrEqualTo to split the dataset into chunks at download them step by step? I wonder how I can construct the actual URL to include the paging filter. Here is what I tried:  http://example.com/wfs.aspx?request=GetFeature&amp;service=WFS&amp;version=1.1.0 \ &amp;typeName=example:example&amp;maxFeatures=50000 \ &amp;FILTER=&lt;ogc:Filter xmlns:ogc="http://www.opengis.net/ogc"&gt; \ &lt;ogc:PropertyIsGreaterThanOrEqualTo&gt;&lt;ogc:PropertyName&gt;OBJECTID&lt;/ogc:PropertyName&gt; \ &lt;ogc:Literal&gt;50000&lt;/ogc:Literal&gt;&lt;/ogc:PropertyIsGreaterThanOrEqualTo&gt;&lt;/ogc:Filter&gt;   This is not a valid URI though... That's why uri-encoded the filter part:  http://example.com/wfs.aspx?request=GetFeature&amp;service=WFS&amp;version=1.1.0 \ &amp;typeName=example:example&amp;maxFeatures=50000 \     &amp;FILTER=%3Cogc%3AFilter%20xmlns%3Aogc%3D%22http%3A%2F%2Fwww.opengis.net \ %2Fogc%22%3E%3Cogc%3APropertyIsGreaterThanOrEqualTo%3E%3Cogc%3APropertyName%3EOBJECTID \ %3C%2Fogc%3APropertyName%3E%3Cogc%3ALiteral%3E50000%3C%2Fogc%3ALiteral \ %3E%3C%2Fogc%3APropertyIsGreaterThanOrEqualTo%3E%3C%2Fogc%3AFilter%3E   This actually works. Is there a "nicer" way to do this? Calculate the area of an irregular cyclic convex polygon A problem about Vandemonde matrix Prove that if every node in a simple graph $G$ has degree $3$ or higher, then $G$ contains a cycle with a chord. How could the Fremen do what they did to the empire in Dune Messiah? How could, and why would, the Fremen's jihad kill 61-Billion people and conquer the known universe?  Their leader Paul was already emperor.  What was left to conquer?  And how could they force this onto Paul when they had no relationship with the Spacing Guild except thru Paul?  If Paul didn't arrange for transportation then how would they get off Arrakis?  And how does a small population of hardened, rugged, but not technologically advanced people do that much conquering in that time?  Also, is there any explanation about how Ix, Tleilex planet and Bene Gesserit planets hold off the wave of jihad? Why would I want to install a snap if I can install via apt instead? Sinking and Sourcing Current to and from a PIC24F Output Pin Sinking and sourcing current refers to current going into and out of the MCU (respectively), right? If you configure a GPIO pin as an output, why would current ever go into the pin (since it's configured as an OUTPUT)? I suppose it depends what the output circuit looks like, if it's tied to the voltage supply rail or ground... maybe I just answered my own question...? CNAME for top of domain? Is it possible to set a CNAME record at the top of a domain? (i.e. @ CNAME www, @ CNAME foobar.com., etc.)  My ISP says that it's only possible to use CNAME's for subdomains but I've read somewhere else that is should be possible even if not recommended. I downloaded the Upwork desktop App on ubuntu 18.04. When I open it with Gdebi package installer I saw this error:    I tried to install gksu manually via sudo apt install gksu but I got this error  Building dependency tree        Reading state information... Done Package gksu is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source  E: Package 'gksu' has no installation candidate   How can I install this software on ubuntu 18.04 (I download it yesturday so it is the most recent version on upwork website) ? How can I use $variable in a shell brace expansion of a sequence? I want to use $var in a shell brace expansion with a range, in bash. Simply putting {$var1..$var2} doesn't work, so I went "lateral"...   The following works, but it's a bit kludgey.    # remove the split files echo rm foo.{$ext0..$extN} rm-segments &gt; rm-segments source rm-segments   Is there a more "normal" way? Installing "firmware-b43-installer" offline Eclipse was working as good as anything on 14.04. I did a clean install of 16.04 and installed Eclipse. But it runs a Java program only once after which it just hangs during subsequent attempts before I remove and reinstall it. I have tried many things, since in the beginning I needed CDT as well. Right now, I just want to remove everything related to eclipse and do a fresh install (remove all the configs and dependencies). Please note that I used Eclipse installer to install Eclipse and the eclipse icon image is also not appearing (the default ubuntu ? is appearing). I am  new to Linux. I am using Ubuntu 11.04 and do not know how to compile and execute C++ program in it. I need to know the commands to Compile and Execute a C++ program in Linux. This question, , seems to indicate $$\nabla_a \sqrt{g}=0.$$ Why is this the case? I've always learned that $$\nabla_a f= \partial_a f,$$ hence surely $$\nabla_a \sqrt{g}=  \partial_a\sqrt{g} \neq 0. $$  Where's the hole in my logic?