Why does Windows' performance degrade over time even when it isn't used? I know that similar questions have been asked before (like  and ), but none of them answer my question. My problem is, as stated in the title, that when Windows isn't in use (some months) its performance degrades. (Boot time goes from ½ minute to 2 minutes) If I boot Windows every day for a week, the boot time shrinks, but I have disabled defragmentation.  The other answers indicate that it might be fragmentation or bit rot. I know for sure that i can't be fragmentation since the hard drive is not use when not booting Windows (except for benchmarking from Linux). However, when benchmarking the drive under Linux (always booting from a separate drive), the drive's performance doesn't drop over time.  Edit: The computer I described in the question runs Windows 8, however I've also experienced this on Windows 7.
Why does Microsoft Windows' performance appear to degrade over time? Windows XP/2003 and earlier (can't attest to Windows Vista, but I suspect it's the same) all appear to become more sluggish over time as applications are installed and uninstalled.  This is not a scientifically tested observation, but more of a learned-through-experience piece of wisdom.  (I've always suspected the registry as being behind the issue.)  Is there any concrete evidence of this degradation occurring, or it just an invalid perception of mine?
Is it acceptable to change the vid column of a term programmatically in the database? I need to move some terms from one vocabulary to another by retaining all their data: translations, aliases, and node references.  Is it acceptable to change its vid column value directly in the database? The terms don't have hierarchy relationships which needs to be handled. How can I ensure my Samsung Series 7 is actually using the Radeon switchable graphics? I have a Samsung Series 7 with the Radeon 6750M switchable graphics. The ATI software lets you force programs to use the dedicated card. However, I'm not convinced it is actually ever using it, as the frame rates on some non-taxing games (Portal, TF2) are merely OK. To make matters worse, it looks like the ATI Catalyst Control has vanished from my laptop. To make it even worse, you can't download the driver and ATI CCC from ATI's site, you need to download it from Samsung, and the ZIP they provide is corrupted.   How can I ensure my Samsung Series 7 is actually using the Radeon switchable graphics? Why didn’t anyone dial Abydos before Daniel solved the mystery of the seventh symbol? From what I recall from the movie, Daniel only finds the seventh symbol... however when he explain they give way to show him the star gate and they put their sequence in the dialing computer. This proves the dialing computer was prepared to dial 7 chevrons.  It’s also stated they’ve also tested the 6 previous symbols in the order they appear on before, one has to assume only to fail when they insert the 7th, making them aware of the fact you can, at least dial 7th chevrons.  With 39 chevrons on the gate and 6 already locked in, that leaves 33 to try to get a lock. Those are not that many not to go and simply try one by one so... how come nobody brute forced the thing? Why are low-rep users rate-limited when posting questions? I just encountered the following error:  Oops! Your question couldn't be submitted because: users with less than 125 reputation can only post questions every 20 minutes; try again later.  Why do you have this rule? Why 20 minutes? I'm an Indian student currently in Singapore as a Research Associate with a TEP valid for five months and have just been selected for an internship in Switzerland this summer.  Is it possible for me to obtain a Schengen visa from the Swiss Embassy in Singapore? How can I find $\gcd(a^m+1,a^n+1)$ with $a,m,n$ positive integers?    I have this idea:  Let $d=\gcd(m,n)$. Then there exist positive integers $x,y$ such that $mx-ny=d$ (WLOG). We shall find $G=\gcd(a^m+1,a^n+1)$.  If $m,n$ are odd, then $d$ is odd, therefore one and only one of $x,y$ is even. We have:  $$a^{ny}(a^d+1)=a^{mx}+a^{ny}=(a^{mx}-1)+(a^{ny}+1)=(a^{mx}+1)+(a^{ny}-1).$$  If $x$ is even and $y$ is odd, then $a^{m}+1\mid a^{mx}-1$ and $a^{n}+1\mid a^{ny}+1$, therefore $G\mid a^{ny}(a^d+1)$. If $x$ is odd and $y$ is even, then $a^{m}+1\mid a^{mx}+1$ and $a^{n}+1\mid a^{ny}-1$, thus $G\mid a^{ny}(a^d+1)$. However, since $\gcd(a^m+1,a^{ny})=\gcd(a^n+1,a^{ny})=1$, so $\gcd(G,a^{ny})=1$, hence $G\mid a^d+1$. We also have $a^d+1\mid a^{m}+1$ and $a^d+1\mid a^{n}+1$, so $a^d+1\mid G$. Thus $G=a^d+1$.  If $v_2(m)=v_2(n)=v_2(d)=k&gt;1$, then there exist some odd numbers $m_1,n_1,d_1$ such that $m=2^km_1,n=2^kn_1,d=2^kd_1$. We shall have $m_1x-n_1y=d_1$, so one and only one of $x,y$ is even, and we can use the same argument when $m,n$ are odd, so $G=a^d+1$.  However, if $v_2(m) \neq v_2(n)$, I cannot find any solutions for this. I think that $G \in \{1,2\}$, but I cannot prove or disprove it. How can I find $G=\gcd(a^m+1,a^n+1)$ if $v_2(m) \neq v_2(n)$ ? Moreover, is there anything from my arguments that can be improved ? When to use "do" in phrases which are not questions? Example: You do need to drink more water.   or   You need to drink more water.   What is the difference? Difference between deportation and removal As I understand it, there are two mechanisms for throwing somebody out of the UK: deportation and removal. Informally, people seem to call both of these "deportation".  What are the differences between them? Who do they apply to? Do they have different effects on the person's ability to return to the UK later? I want to install Windows XP on my desktop computer (only XP), but my CD drive is not working.  I've only found installation tutorials on how to install it on the pen drive rather than from the pen drive.  How can I install Windows XP from a USB flash drive? After removing any part the rest can be split evenly. Consequences? Let $S$ be a finite collection of real numbers (not necessarily distinct). If any element of $S$ is removed then the remaining real numbers can be divided into two collections with same size and same sum ; then is it true that all elements of $S$ are equal ?  (I know the result is true if the &quot;reals&quot; are replaced by &quot;integers&quot;.) Image of the union is the union of the images $$ f\left(\bigcup\limits_{\lambda \in \wedge} A_{\lambda}\right) = \bigcup\limits_{\lambda \in \wedge} f(A_\lambda)$$  Let $b \in f(\bigcup\limits_{\lambda \in \wedge} A_{\lambda})$ $\rightarrow b=f(a)$ for some $a \in (\bigcup\limits_{\lambda \in \wedge} A_{\lambda})$.  Since $a \in (\bigcup\limits_{\lambda \in \wedge} A_{\lambda}) \rightarrow a \in A_{\lambda}$ for some $\lambda \in \wedge$.  Since $b=f(a)$, then $b \in f(A_{\lambda})$ for some $\lambda \in \wedge$.  $\rightarrow b \in \bigcup\limits_{\lambda \in \wedge} f(A_\lambda)$ $\rightarrow f(\bigcup\limits_{\lambda \in \wedge} A_{\lambda}) \subset \bigcup\limits_{\lambda \in \wedge} f(A_\lambda)$.  I used a similar argument to prove $\bigcup\limits_{\lambda \in \wedge} f(A_\lambda) \subset f(\bigcup\limits_{\lambda \in \wedge} A_{\lambda})$.  Which shows $ f(\bigcup\limits_{\lambda \in \wedge} A_{\lambda}) = \bigcup\limits_{\lambda \in \wedge} f(A_\lambda)$.  Please let me know if this is valid. If $X$ and $Y$ are independent $N(0,\sigma^2)$, then $X^2+Y^2$ and $X/Y$ are independent? If $X$ and $Y$ are independent, then $X^2+Y^2$ and $X/Y$ are independent? I was solving the problem for the case that $X$ and $Y$ are independent $N(0,\sigma^2)$.  So i found that $X^2+Y^2$ is negative exponential, $X/Y$ is Cauchy distribution. How can i prove that $X^2+Y^2$ and $X/Y$ are independent?  Also, what it will be if the case for general random variable $X$, $Y$ with  $X^2+Y^2$ and $X/Y$ are defined? Name for the center amplitude of a sine wave I am trying to find the name for the value at the center of a sine wave $$ y(t) = A\sin (kx \pm \omega t+\varphi) + D $$ i.e. the offset $D$ of the wave in the $y$-direction.  calls it Center Amplitude, but further googling this name is difficult and does not provide any further sources. I also found the expression , but I'm not sure that it refers to the same thing. Is there a commonly used name for the $y$-direction-offset of a sine wave? Do I need a UK or Ireland transit visa when flying from the US to a Schengen country? I am travelling to Budapest and therefore have a Schengen Visa. I hold an Indian passport and a valid US visa. I'm travelling from Chicago-Heathrow-Budapest and returning by Budapest-Dublin-Chicago.  Would I need a transit visa for UK/Ireland?  UPDATE  Hoping this will help someone someday.   I was not allowed to board my return flight (BUD-DUB-ORD) because I do not hold an overnight Irish Transit Visa. They said I could have transited happily if the connecting flight was in the same day, but because I would have to originally land at 10 PM and catch the connecting flight next morning at 10 AM, I needed a transit visa. Well, I thought it was BS, but couldn't help comply with the rules. I booked another last minute ticket and flew via Warsaw via LOT. How to make a cyclorama I can create a collection of pictures giving a 360-degree view from a certain spot, just taking a bunch of photographs from the same spot but in a different direction.  However, what software could I use (on Windows) to stitch these images together to get one big image?  I prefer something that would stitch them together without showing any seams. I'm currently the proud owner of Frost the horse. What I want to know is, what will happen to him if I ride another horse?  Obviously nothing will happen as long as I have him in sight, e.g. I'll be able to ride Frost to make him my horse again.  Scenarios  But what will happen if, before I get back on Frost, I fast travel somewhere? Will he return to where I originally stole him, will he disappear forever, or can I own two horses simultaneously?  Ownership?  If he goes back to where I originally stole him, will I have to steal him again, and therefore never be his true owner again?  Two Horses?  The reason I'm asking is because I want to get Shadowmere (the Dark Brotherhood horse) while keeping Frost. Is it possible to do this, or will riding Shadowmere make me lose Frost forever? Do the SO admins have any plans to release the underlying code for SO at all? I appreciate that the code may be part of their competitive advantage, but it strikes me that the underlying system would work for any topic, not just programming.  I am not advocating this, just curious really, but figured it might be under consideration as most of the value in SO is in the questions and answers, which have been released under a relatively open CC license. C programming, why does this large array declaration produce a segmentation fault? Is “all women who are mothers of daughters” right? Is the expression      All women who are mothers of daughters are here.   correct? I mean every woman who has at least one daughter is here. Find the value of : $\lim_{n\to\infty}\prod_{k=1}^n\cos\left(\frac{ka}{n\sqrt{n}}\right)$