Wikipedia:Reference desk/Archives/Computing/2020 June 1

= June 1 =

Acrobat Reader DC problem, again
I asked this about six weeks ago. I am trying to use Adobe Acrobat Reader DC to read and print PDF files. As is often the case here, someone told me that I was conflating Adobe Acrobat with Adobe Acrobat Reader, and that I needed to specify what I was trying to do with them so that they would know what to lecture me about. Another editor, properly, lectured them back for not having seen that I had already answered that I was trying to use the most current version of the Reader to view and print PDF files. Here, again, is the problem. I have installed Adobe Acrobat Reader DC from the Adobe web site. After a while, something happens so that when I launch a PDF, or when I click on the icon for Adobe Acrobat Reader DC on the desktop, Adobe Acrobat Reader opens as a Background Process. That is, the Task Manager thing lists it as a Background Process. This means that I can't do anything with it. I know an answer, which is that I can uninstall it, and re-install it from the Adobe web site, and then it runs as an App in foreground, for a while. Then it gets into being a background process again. So the question is what should I do, other than re-install it maybe once a week.

My first thought was to call Adobe technical support. Unless I have misread something, they won't take technical support calls for something that I didn't pay for.

I could install Adobe Acrobat full-up on a trial basis, but I know that when the trial period is over, I don't want to pay for it.

Is there either an alternate freeware program or a low-cost program that I can install as an alternative to Adobe Acrobat Reader DC?

Does someone have a suggestion as to what may be causing this to happen and what to do about it?

Robert McClenon (talk) 02:48, 1 June 2020 (UTC)
 * What OS are you running and what sort of machine? There's plenty of alternatives for Linux boxes and there seem to be a fair few for Android phones.  If you're stuck with Windows pre-10 I can't help, but fully updated Win10 has the ability to run native Linux images.  So far I've only run a few tests using BASH but it is looking good.  You can either start BASH directly, or else load up an Ubuntu window.  Don't know how full the provision is, but it's worth a coffee break fiddling. Martin of Sheffield (talk) 08:35, 1 June 2020 (UTC)


 * I suggest you take a look at List of PDF software. FWIW I use Sumatra PDF.--Shantavira|feed me 10:15, 1 June 2020 (UTC)
 * +1 for SumatraPDF. If it doesn't suit your needs you can try Foxit Reader but I'd suggest Sumatra first since it's very lightweight and won't have this kind of problem. 93.136.103.94 (talk) 10:57, 1 June 2020 (UTC)
 * This sounds like some kind of odd problem with your machine and not Acrobat Reader specifically. I have never had this occur on any Windows 10 machine I've used Acrobat Reader on. Does this happen with any other programs that you've noticed?
 * Mozilla Firefox, Google Chrome, and probably some other web browsers now can open PDFs themselves and have been able to for several years. This includes PDFs saved on your machine. To open one, just open the file in the browser; do a Web search for, for instance, "firefox open file" if you're not sure how. If you want, you can make your preferred browser the default for opening PDFs, which means it will be used for things like opening them when double-clicked in File Explorer. For this, Web search "windows 10 default." --47.146.63.87 (talk) 15:17, 1 June 2020 (UTC)
 * Microsoft Edge can also open PDF files. Brianjd (talk) 15:21, 1 June 2020 (UTC)
 * Oh, one thing to note is that once in a while the browser PDF readers will have trouble with a PDF, and they also don't support the fancy extra features that Acrobat has, such as filling in form fields. Acrobat is basically the only thing that fully supports every single feature of PDF in all of the format's terrifyingly gory detail. The browser PDF readers are intended as "good enough" basic readers. --47.146.63.87 (talk) 15:51, 1 June 2020 (UTC)


 * We know from an earlier question that the OP is using Windows 10. If you run Windows 10, expect odd problems with your machine becuase of those updates Microsoft keeps forcing on everyone. (By the way, if you already have an odd problem with your machine, trying to back up the whole machine now might be a bad idea.) Brianjd (talk) 15:24, 1 June 2020 (UTC)
 * +1 to that too (regrettably, as a 20+ years Windows ex-user). If you really need Windows 10, you should try getting your hands on an Entreprise edition if you can, I heard they're more stable. 93.136.103.94 (talk) 19:21, 1 June 2020 (UTC)
 * In my personal experience I've had no real issues with Windows 10 Home/Business. One thing I do is always wait a bit before installing Windows updates rather than install them immediately (usually on Patch Tuesday) which generally means any problematic updates get reverted or fixed beforehand. Fortunately this is easy now in recent Windows 10 versions as you can temporarily pause Windows updates. In general this is good practice for any software unless you're fine with being a quasi-beta tester, unless it's software that gets well-tested before official release. (For example, stable Firefox releases are usually fine, because testing is done beforehand in the unstable and nightly branches.) --47.146.63.87 (talk) 02:27, 5 June 2020 (UTC)

Restarting Windows
My problem, or perhaps symptom, was that Acrobat was loading as a background process, and then it can't be switched to in foreground, and so doesn't view and print. That's a problem. So I restarted Windows. Then I restarted Acrobat Reader DC by launching a PDF. The PDF launches fine and prints. This provides a constraint on what the problem has been. There wasn't anything wrong with the way Acrobat was installed. So there was something wrong with the way Windows and Acrobat were interacting. My guess is that there was some sort of a leftover of Acrobat, similar to having a zombie process in Unix. I might still look for an alternate PDF viewer, but the problem isn't with Acrobat as such, but with Windows getting a dislike to Acrobat. Robert McClenon (talk) 19:14, 1 June 2020 (UTC)
 * Is your Acrobat Reader a Windows Store app? That sort of thing is known to cause problems in Windows 10. Alternatively, Acrobat Reader depends on some kind of background process (supposedly used for quicker startup) which starts with your computer and idles in the background even after you close the Reader (tho you can safely kill it in Task Manager), this could be contributing to the problem. In addition, SumatraPDF has a simpler PDF renderer (MuPDF) so it isn't as prone to bugs and security holes as Acrobat (it doesn't do forms and JavaScript), might be worth installing simply on that basis. However you're correct in what you wrote here. 93.136.103.94 (talk) 19:21, 1 June 2020 (UTC)
 * I found [//community.adobe.com/t5/acrobat-reader/reader-dc-runs-as-a-background-process/td-p/9890111] [//community.adobe.com/t5/acrobat-reader/dc-reader-only-run-as-a-background-process/td-p/9011014] which suggest this has been a long standing problem with Adobe Reader for some people. Windows updates have fixed it (rather than created it) for some. However there's no clear resolution. You can try using Adobe's cleaner tools and reinstalling but it doesn't sound like that works for everyone. It seems for most or all people who have reported this problem, running Adobe Reader in a different user account appears to resolve it suggesting whatever the problem is, there's some interaction with something in the user account. But I also found this [//ghisler.ch/board/viewtopic.php?t=47895] which is interesting. I'm guessing your not running Total Commander? But are you running anything with admin privileges which you are using to open PDFs? I do hope you're not running any browser with admin privileges but maybe if you are or something else e.g. PowerShell, Cmd, some file manager, some phone transfer utility, some backup tool, and using it to open Adobe Reader probably via trying to open a PDF, that's likely the cause of your problems. Note that if you install something and then run it from the install option, this sometimes results with the program running with admin privileges (until you quit it). Likewise, I'd avoid trying to open PDFs from any installer just in case.  Also, although as mentioned by one of the forum posters, disabling the protected mode in Adobe Reader  [//stackoverflow.com/questions/47512454/diagnostics-process-doesnt-open-pdf-file-using-adobe-reader] [//community.adobe.com/t5/acrobat-reader/windows-10-cannot-open-pdf-files-in-reader-dc/td-p/7525324?page=1] may resolve the problem, I strongly recommend against it. As some of the earlier answers have attested to, modern PDFs can be very complicated beasts with scripting and other such stuff which means a lot of complicated code in the reader and so a lot of attack surfaces. The protected mode in Adobe Reader is there for a reason.  If this doesn't help, while not a solution per se, some of the forum threads mentioned something I think you missed. Unless you're running with extremely restricted privileges with no possibility of elevation, or maybe some weird thing like Windows S, AFAIK it's not true you cannot do anything to background processes. You should still still be able to end task/kill them. I suspect, especially given you've now confirmed restarting fixes it, you'll find that killing all Adobe Reader processes or if that fails, all  Adobe processes will resolve the problem without requiring a restart.  Nil Einne (talk) 18:11, 3 June 2020 (UTC)

AMOLED for PCs
For some years now we've had AMOLED screens on cell phones, which have true blacks since pixel brightness can be apparently continuously toned down to zero - unlike usual LCD screens which still emit glow even at full black with darkest possible settings. Why don't we have AMOLEDs for computer screens? If we do what are they called / why am I only finding cellphones? Thx 93.136.103.94 (talk) 10:55, 1 June 2020 (UTC)
 * What about just OLED? I don't believe the active-matrix part is necessary for the "blacker blacks" feature you want. I found a $3,999 OLED monitor on Newegg. Elizium23 (talk) 11:00, 1 June 2020 (UTC)
 * As mentioned, AMOLED is OLED. The AM part refers to the layer that charges the pixels, not the light producing diodes. AMOLED is popular in handheld devices because it can use less power under common handheld circumstances (the colors don't change a lot) and the backplane tends to be more flexible than a standard OLED. So, are you asking about OLED (and AMOLED) monitors or are you specifically looking for an AMOLED backplane on a monitor? Both exist. They aren't the chep monitors, so they won't turn up in the first few pages of a monitor list if you sort by price. Some places won't even sell them because they only deal in cheap equipment. There is a catch though. From the television world, it was discovered that AMOLED is more prone to burn-in than OLED. The "store-n-charge" backplane is the issue, not the light emitting diodes. Computer usage will make burn-in events more frequent. The technology to fight burn-in is not cheap. So, to jump from OLED to AMOLED in a computer display is going to be more expensive. Some gamers want it. They are using AMOLED televisions as gaming monitors. The market is there, but it is very tiny. That is why you will find very few offerings in AMOLED that are strictly computer monitors. But, they do exist. Now, I need caffeine. I've forgotten the question three separate times in attempting to write this response. 97.82.165.112 (talk) 11:34, 1 June 2020 (UTC)
 * Screensavers are coming back, baby! (Though typically you can just have the display "sleep" automatically which is better to save power.) --47.146.63.87 (talk) 15:41, 1 June 2020 (UTC)


 * Well I just want a screen where pixel brightness goes down to zero so it can be comfortably used in a pitch dark room without eye irritation. Is OLED enough for this? While power consumption (and refresh rate, etc.) doesn't matter to me, $4k sounds like far too much for my budget. Is there something non-Dell in the several hundo range? ;) 93.136.103.94 (talk) 19:12, 1 June 2020 (UTC)


 * The Panasonic Toughbook 55 laptop can set the screen brightness low enough to be just barely readable in total darkness, even lower so that it is completely dark unless you are wearing night vision goggles, or bright enough to be easily readable in direct sunlight. So it can be done, but the Panasonic Toughbook 55 is a specialized piece of equipment designed for use on the battlefield or in police cars, and thus is quite expensive. I know of no regular monitor that can do that. You could try a layer or two of this: [ https://www.amazon.com/dp/B07W7LB5XC/ ]. --Guy Macon (talk) 22:10, 1 June 2020 (UTC)


 * There is not much difference these days between "televisions" and "monitors" since fundamentally they're the same thing. (I have noticed the term "display" seems to be becoming more popular as a catch-all term, probably for this reason.) The difference is mostly features and the housing, as "televisions" are often mounted on a wall or mount. DVI, HDMI, and DisplayPort are all interchangeable with the appropriate cables/adapters. Even a VGA connector can be hooked into any of those, though it may require an analog-to-digital converter if the computer's graphics controller can't be configured to put digital output on the VGA connector rather than analog. (Some "televisions" have a VGA input though these are becoming rarer so I'm not sure too many AMOLED TVs will have them.) --47.146.63.87 (talk) 15:41, 1 June 2020 (UTC)
 * I don't know about VGA but my TVs have SCART. They're several years old tho. 93.136.103.94 (talk) 19:12, 1 June 2020 (UTC)
 * SCART is unheard-of this side of the pond. Here TVs use RCA connectors for analog non-tuner input, or the mini-DIN for S-Video. Until the 2000s PCs near-universally used the VGA connector for video output which means fancier TVs often had a VGA input, as did things like projectors. Some still do but it's becoming less common as PCs have mostly phased-out VGA. --47.146.63.87 (talk) 09:53, 2 June 2020 (UTC)
 * While the overall packages are becoming very similar, televisions are designed for quick changes while monitors are designed for crisp definition. It is possible to see the difference if you know what you are looking for. If I watch a movie on a computer monitor and it pans left or right, I can see the stutter on my computer monitor. Similarly, if I display a presentation on my television, I can see the fuzz around the edges if the letters. For almost all purposes though, you can display HDMI out to nearly all modern monitors and televisions and it will be satisfactory. 97.82.165.112 (talk) 22:39, 1 June 2020 (UTC)
 * Right, I didn't want to get into the weeds. They tend to be optimized for different things, but I think a lot of users don't care much. Those who care are gamers, cinephiles, etc. who pay close attention to things like refresh rate. --47.146.63.87 (talk) 09:53, 2 June 2020 (UTC)