Wikipedia:Reference desk/Archives/Computing/2015 January 29

= January 29 =

Cryptowall 3.0 and system reset
If a computer running Windows 7 has the great misfortune to get Cryptowall 3.0 and you decide to set it back to the factory image stored on a separate partition, will it erase the virus entirely from your computer or is Cryptowall 3.0 known to worm its way into this partition as well? Apologies if I'm using improper terminology, and no, it's not my computer before anyone decides to start having "small talk" as it were. Sir William Matthew Flinders Petrie &#124; Say Shalom! 9 Shevat 5775 03:01, 29 January 2015 (UTC)


 * I have seen some reports that CW may encrypt the recovery partition, but I have not seen that it infects it. --  Gadget850talk 13:02, 29 January 2015 (UTC)
 * Ah all right. I did reset the unfortunate person's computer (which now has significantly better security), so it doesn't look like the partition was encrypted (thankfully). Sir William Matthew Flinders Petrie &#124; Say Shalom! 9 Shevat 5775 16:55, 29 January 2015 (UTC)

USB drive ejected from an off computer
What happens if I shut down my computer without clicking to eject my USB drive, then eject it manually when my computer is off. Is it the same as ejecting while it is on? 75.80.145.53 (talk) 03:26, 29 January 2015 (UTC)


 * When you say eject it manually, do you mean you physically pull it out? Sir William Matthew Flinders Petrie &#124; Say Shalom! 9 Shevat 5775 03:38, 29 January 2015 (UTC)


 * "Ejecting" is mainly about signalling to the operating system that it needs to actually write data to the USB device, rather than storing it in a write cache - which it does for performance reasons. Shutting down your computer will cause write caches to be written to the device and thus "ejected". And so you're fine to pull the USB device out of the USB socket; the risk of data loss associated with pulling out when the computer is on is completely absent. --Tagishsimon (talk) 03:51, 29 January 2015 (UTC)


 * As far as I understand, shutting down your computer will only cause write caches to be written if you select "Shutdown..." from your appropriate start menu or otherwise issue a shutdown command. If you just physically pull the plug, the computer won't get a chance to write the write caches and you may end up with lost data, or even a corrupt filesystem. J I P  &#124; Talk 10:38, 29 January 2015 (UTC)


 * [OR warning] I've removed USB drives many hundreds of times without "safely removing" or "ejecting", and I've only once had a problem. I don't recommend the practice, especially if the data on the drive is important (mine is always a copy of data held elsewhere).  As long as you don't remove the drive whilst it is actually being actively written to, the integrity of the drive is usually maintained.  If any of the data on your drive is your only copy, then you would be wise to follow recommended procedures, and, if you have accidentally unplugged it with the computer off, plug it in again before switching on so that the operating system (if it has maintained buffers) can write any remaining date before ejecting.    D b f i r s   13:05, 29 January 2015 (UTC)


 * When you insert a device like USB flash, Windows sets a dirty bit on the device. If you properly eject it the bit gets reset. If you improperly eject it the bit stays set and is detected when you mount it again and Windows tells you the device may be corrupt and prompts to scan. --  Gadget850talk 13:17, 29 January 2015 (UTC)
 * Don't modern (post-XP) versions of MS-Windows disable the write cache for removable storage? Therefor it is safe to just pull the drive out without telling Windows that you are about to do it. Coming back to the OP's question, even if the write-cache was enabled, when you shutdown your computer properly, the write cache for all drives, removable or not, will be written. Therefore, it is safe to remove the drive when the computer is powered down. Hibernation and Sleep might be a different case. LongHairedFop (talk) 15:28, 29 January 2015 (UTC)


 * Here is a good article on this. --  Gadget850talk 16:13, 29 January 2015 (UTC)

How to create animation/image sequence with alpha channel?
I'm trying to create a simple animation with a moving filmstrip, like this one:. I'm trying to keep the animation as simple as possible, so it basicly just consists of two different frames, one like that, and the other shifted so that the vertical bar is in the horizontal middle. Alternating those two at 25fps (using Adobe Premiere Pro 2.0) does give me a pretty neat animation already.

Okay, first level of trickery is that it requires an alpha channel, to give me an easily determinable image in the middle. I can do that just fine using Paint Shop Pro, cutting out that center piece in both of my two alternating frames and save each frame as a PSD with an alpha channel. Works just like a charm when loading those two frames into Premiere Pro.

Second level of trickery is that I wanna create a DVD menu out of this animation, where the animated film strip first appears in full size filling the whole image, then have it shrink down and move to the left at the same time. In order to achieve that, I've already created two image files seven times as high as the original two, where I've copy-pasted the original filmstrip image seven times over, so that the result, when shrunk down, will still fill my whole DVD menu from top to bottom. Loading those two higher animation frames into Premiere Pro and have them alternate each other does also work, where at first, most of the vertical image information is outside the frame, until I shrink it down.

But here's the real catch: I wanna try out several different timing and resizing methods, in order to find out which works with my audio, overall menu animation timing, etc. And it's close to impossible to try all those different methods and speeds seamlessly and easy on two tiny alternating frame files, each only a frame long, in my Premiere Pro timeline. What I'd need would be a single animation file with variable length in my timeline, and no matter how long I make it in duration, it's still just those two alternating frames looped, always at the same speed.

Now, you may tell me to just render one animation clip out as an actual video and load that back into Premiere Pro. But the problem is that I'll lose both my alpha channel that way, as well as all image information outside of the frame borders, so I won't be able to shrink my animation.

So, what I need is a way to create a simple looped animation file out of these two frames, complete with an alpha channel and with the animation being at an arbitrary pixel height, that I'll then be able to load into Premiere Pro, where I'll be able to change the clip's duration in my timeline and only change my animation's length, but not its speed. A tiny animation creation program would be best to load my two frames into, because I'm so short on disk space that it shouldn't be bigger than maybe 30MB at absolute max. I guess if I had FinalCut, I could just create a series of nested timelines, but I don't. --87.180.197.207 (talk) 05:37, 29 January 2015 (UTC)


 * Nevermind, I was just too dense. I've solved the whole problem by creating the filmstrip's up-and-down movement in Premiere Pro instead, using keyframes. --87.180.197.207 (talk) 06:25, 29 January 2015 (UTC)

Photoshop problem
Hey guys I’m drawing in photoshop and I don’t know how but no matter what color I choose, the brush paints a certain shade of pink in different intensities, and I can't change image mode because it's greyed out. I tried re-starting the program, even the computer, and so far it's been futile. Does anyone know how I can fix this?--Irrational number (talk) 13:13, 29 January 2015 (UTC)


 * One thought is that you might have your PC set to a limited color palette, say 256 colors. That's usually set along with resolution, although only very old PCs would be likely to have a 256 color option.  If your PC has already used up the other 255 colors, there might only be one color left.  StuRat (talk) 13:16, 29 January 2015 (UTC)


 * What happens when you open an existing non-pink image? This thread may be helpful . The first thing I'd try is creating a new monitor profile. Or just bring out the GIMP :) SemanticMantis (talk) 16:30, 29 January 2015 (UTC)


 * What do you see on the title bar? It will show the file name @ . --  Gadget850talk 17:59, 29 January 2015 (UTC)
 * Pink paint, sounds to me like you might be inadvertently painting a layer mask? Are you sure you have the correct brush tool and option selected? Vespine (talk) 23:59, 29 January 2015 (UTC)

Windows update killed wireless connections?
A couple of hours ago, I installed the latest update for Windows 8, and immediately upon completing the restart, I observed that I had no wireless networks whatsoever: I was getting an icon that I normally only see when I'm using my computer in the car, and nothing I could do would restore anything. I borrowed another laptop at this point, and with it I was able to see that the building's network was indeed still running; it was a problem with my computer. I then performed a system restore, and since that point everything's been running without any problems. What was in this update that would have affected my network usability? Can anyone imagine what happened? Nyttend (talk) 17:47, 29 January 2015 (UTC)


 * Sounds like a bug to me. Specifically, I bet something in your wireless configuration is different from what they tested the update on, and so they missed this problem.  This seems more likely if you are using some older wireless equipment or drivers which Windows 8 no longer supports (perhaps it never did, but it continued to work using the code Windows 8 inherited from earlier versions, until they made this change). StuRat (talk) 17:50, 29 January 2015 (UTC)


 * I bought the computer in late 2013 (late November or early December), and it came with Windows 8 preinstalled, if that's at all relevant. Nyttend (talk) 17:52, 29 January 2015 (UTC)


 * Were the wireless hardware and drivers also pre-installed ? If so, I'd hope that whoever did so would have checked to ensure that they were supported by Windows 8. StuRat (talk) 17:55, 29 January 2015 (UTC)


 * January 13 was the last Patch Tuesday, so you probably got one of the patches listed here. You can try Windows updates, install the patches one at a time and see which one breaks. Once we know the patch in question we can work towards a resolution. --  Gadget850talk 17:56, 29 January 2015 (UTC)
 * Computer was bought on 7 December 2013. Presumably they were pre-installed; I'm really not much of a computer whiz, and I don't know where to go for drivers or hardware.  I've never had to have repairs performed on this machine; it has all of the original hardware.  There may have been some interaction with security software — I had to run the system restore tice, because a small part of the first run failed (and it didn't resolve the connectivity problem) and gave me a note suggesting that I disable my antivirus.  After I turned off AVG Antivirus, everything went fine, and yes I did remember to turn it back on.  Nyttend (talk) 17:58, 29 January 2015 (UTC)


 * Comment: When updating, think about the probability of risks. Microsoft is very slow to release updates. So if one doesn’t update as soon as they are release, one computer could have been venerable for months– BUT the updates (compared to say Debian) are relativity untested. So, I would say, that next time, wait until you can google too see if the update has any problematical bugs. Also run your Microsoft OS in  Virtual machine. Then if everything suddenly goes Pear-shaped on an update or virus infection/etc, (at a time where you need your computer to work and you don't have the free time to sort it out there and then), one can then simply go back to the uncorrupted version.--Aspro (talk) 18:52, 29 January 2015 (UTC)


 * That sounds fine in theory, but with a dozen updates a week, that would be a major time commitment to research each update before installing it. And Microsoft is no help.  Their summary of what the updates does either says "addresses issues in Windows" or "addresses a security risk", with no more detail than that.  They provide a link for "more info", but it doesn't take you to info on that particular update, but rather it dumps you onto their update site and leaves you to try to track down each update. StuRat (talk) 19:11, 29 January 2015 (UTC)
 * In practice, I find it a breeze (compared to running widows naked)so it think we have have our wires crossed. What are we talking about, bells and whistles updates or security issues. Doesn't matter. Running Microsoft in a VM (on say Dabian) means that if one is struck by a Zero-day attack or whatever, ones exposure is limited. And one can quickly roll back. If one then discovers a serious bug...which stops you using your computer...Just roll back. It is only then you need to google. So no major time commitment. Here is a step by step guide:--Aspro (talk) 20:01, 29 January 2015 (UTC)


 * But it could be the OP got a recommended update (such as a hardware specific one) which would be listed there but I think may still come out on patch Tuesday. And does it list all security updates including those that are hardware specific? From the description, I think it doesn't. If I was the OP, since they've apparently rolled back I would actually look at the updates that are available for them and uninstalled. In particularly, I'd look first for anything related to their wireless networking hardware. Nil Einne (talk) 19:23, 29 January 2015 (UTC)


 * If updates are set to automatic, then this will happen again. Until we know the particular update the system is open to the same issue occuring again. --  Gadget850talk 19:30, 29 January 2015 (UTC)


 * Yeah I was thinking the same thing. The OP may want to also turn off automatic updating in the interim while they check out which updates and try to work out which one is the problem. Alternatively they could just assume something weird went on and it won't repeat itself Nil Einne (talk) 20:55, 29 January 2015 (UTC)


 * In general, one thing you can do in this situation is temporarily turn off automatic updating, manually install only security updates for a week or so, then reenable automatic updating. Windows 8's installed base is large enough that any bug in the updates will almost certainly affect a very large number of people (especially when it affects hardware that shipped with Windows 8), many of whom will notify Microsoft (either explicitly or perhaps via telemetry), and a week is probably enough time for them to fix it or temporarily pull the update until it's fixed.
 * Of course, a security update could be the cause of the problem. In that case you would have to hold off on installing the security updates too (which is not ideal but is probably safe enough) or else try to identify the broken one. -- BenRG (talk) 23:37, 29 January 2015 (UTC)


 * Patch Tuesday of February 13 had eight patches. Unless previous updates were missed, there should be only these eight patches. Applying them one at a time is not going to be an arduous task. If one of the updates kills wireless, then we can look more deeply into that particular update. These were all security patches: nothing pops at me as affecting wireless directly but one of the involves Radius. --  Gadget850talk 13:20, 30 January 2015 (UTC)

Wifi tethering *from* a laptop
I've seen lots of discussion about tethering from a cell phone to a laptop, but I want to go the other way: From my laptop, which has wifi, to my Obi, which only has wired input. Is that possible? That is, can I hook up my toll-free land line at, say, the hardware store? — kwami (talk) 20:28, 29 January 2015 (UTC)


 * If I understand correctly: WiFi → Laptop → Wired → Obi. You could try this by going to the adapter settings and bridging the wired and wireless adapters. The Obi will need a static address. Might be simpler to buy the Obi wireless adapter. I have used the bridging, but never on the Obi. --  Gadget850talk 22:19, 29 January 2015 (UTC)


 * Thanks! Yes, simpler that way, but I shouldn't be buying more stuff.  — kwami (talk) 22:51, 29 January 2015 (UTC)
 * The "Internet Connection Sharing" option (in MS-Windows 7 and later) should be able to bridge your Wifi connection and ethernet connection together. It should be possible to allow DHCP to pass through the bridge; this way both your laptop's and Obi's ethernet card will get a IP address from your WiFi source. LongHairedFop (talk) 11:54, 30 January 2015 (UTC)
 * I haven't used ICS in a decade, but that should work. --  Gadget850talk 13:13, 30 January 2015 (UTC)
 * Lovely! I'll give it a try.  — kwami (talk) 19:42, 30 January 2015 (UTC)

Language/Toolkit for Lightweight Linux GUI Programming
Is there a language/toolkit that lets you program a simple Linux GUI by drawing the windows and adding objects and callbacks (a la Visual Basic on a Windows computer)? By simple, I mean something like MS Paint or Freecell: a few menus, dialogue boxes, and so on. I will write most of the program internals in C, but I don't want to deal directly with API calls for what will essentially be a lightweight front end. Thanks! OldTimeNESter (talk) 22:02, 29 January 2015 (UTC)


 * There are loads of options. If you are a C programmer, you might find the GTK+ API to be your most platform-portable C GUI toolkit.  A GUI-based GUI-builder, Glade for GTK+, also exists.  Nimur (talk) 23:48, 29 January 2015 (UTC)
 * Honestly, I'm a bit overwhelmed by the number of options. I don't want to invest considerable time in learning to use something, only to find out down the line that it doesn't really fit my purpose. GTK+ looks very promising, though; I'll definitely check it out. OldTimeNESter (talk) 09:27, 31 January 2015 (UTC)