# Computer interrupts **URL:** \ **Category:** Factual Questions\ **Created:** [February 25, 2014, 4:47am UTC](https://boards.straightdope.com/t/computer-interrupts/682195 "2014-02-25T04:47:22Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![Daylate](https://avatars.discourse-cdn.com/v4/letter/d/9dc877/32.png) [@Daylate](https://boards.straightdope.com/u/Daylate)\ **Post date:** [February 25, 2014, 4:47am UTC](https://boards.straightdope.com/t/computer-interrupts/682195/1 "2014-02-25T04:47:22Z")
The past few days I’ve noticed that my computer (Desktop, Windows XP Pro Edition, all service packs installed) has been running quite a bit slower than normal. I checked on Process Explorer , and found that from 12% to 30% of the CPU is being taken up by a process called “Interrupts”, described in Process Explorer as “Hardware Interrupts and DPC’s”. Now I have a vague idea of the concept of these interrupts, but not enough to analyze this. They have never been a problem before, nor such a resource hog. Have run Malwarebytes, without finding anything. If anyone of this Board has an idea about what this is, I would really appreciate your input. ---
**Author:** ![Isilder](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@Isilder](https://boards.straightdope.com/u/Isilder)\ **Post date:** [February 25, 2014, 9:27am UTC](https://boards.straightdope.com/t/computer-interrupts/682195/2 "2014-02-25T09:27:48Z")
Often the hard drive having problems You can confirm using control panel, administrative tools, event viewer… See here for more ideas on the exact causes and fixes [http://forum.sysinternals.com/high-cpu-usage-for-hardware-interrupts\_topic2064\_page6.html](http://forum.sysinternals.com/high-cpu-usage-for-hardware-interrupts_topic2064_page6.html) ---
**Author:** ![Daylate](https://avatars.discourse-cdn.com/v4/letter/d/9dc877/32.png) [@Daylate](https://boards.straightdope.com/u/Daylate)\ **Post date:** [February 25, 2014, 7:47pm UTC](https://boards.straightdope.com/t/computer-interrupts/682195/3 "2014-02-25T19:47:09Z")
I opened the “Event Viewer”, and evidently don’t understand how that is supposed to help. All I was able to see is a whole bunch of options like Application, Security, System, and so forth, and opening these leads one to another bunch of options, none of which I could find that mentions Interrupts. I guess I’m not a good enough computer nerd to figure this one out. If you have any further advice here I’m all ears. ---
**Author:** ![Voyager](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/voyager/32/133_2.png) [@Voyager](https://boards.straightdope.com/u/Voyager)\ **Post date:** [February 25, 2014, 8:23pm UTC](https://boards.straightdope.com/t/computer-interrupts/682195/4 "2014-02-25T20:23:10Z")
[Here is the wikipedia page](http://en.wikipedia.org/wiki/Interrupt) on interrupts. Ever wonder how the processor knows how to stop what it is doing and handle a keystroke or a mouse click of data from a disk? The device posts an interrupt, which causes the cpu to transfer control to an interrupt handler which processes the request. So if a device is posting too many interrupts for some reason, performance of a program may suffer. Back when I was in college everyone learned how to write interrupt routines. I guess that this isn’t taught any more. ---
**Author:** ![Daylate](https://avatars.discourse-cdn.com/v4/letter/d/9dc877/32.png) [@Daylate](https://boards.straightdope.com/u/Daylate)\ **Post date:** [February 25, 2014, 10:37pm UTC](https://boards.straightdope.com/t/computer-interrupts/682195/5 "2014-02-25T22:37:44Z")
Good God! Looks like I may be into a scrubbing and reinstallation of the operating system. :(:eek: ---
**Author:** ![Tim\_T-Bonham.net](https://avatars.discourse-cdn.com/v4/letter/t/46a35a/32.png) [@Tim\_T-Bonham.net](https://boards.straightdope.com/u/Tim_T-Bonham.net)\ **Post date:** [February 26, 2014, 11:04am UTC](https://boards.straightdope.com/t/computer-interrupts/682195/6 "2014-02-26T11:04:34Z")
Like Isider said, often a messed-up hard drive is the most likely culprit. A possible fix for this is a complete backuo, low-level reformat, and reimaging. Or even a full defrag & disk cleanup (the type that takes 10-20 hours to run) may improve things. ---
**Author:** ![Isilder](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@Isilder](https://boards.straightdope.com/u/Isilder)\ **Post date:** [February 26, 2014, 11:46am UTC](https://boards.straightdope.com/t/computer-interrupts/682195/7 "2014-02-26T11:46:44Z")
> [@Daylate](#): > > I opened the “Event Viewer”, and evidently don’t understand how that is supposed to help. All I was able to see is a whole bunch of options like Application, Security, System, and so forth, and opening these leads one to another bunch of options, none of which I could find that mentions Interrupts. I guess I’m not a good enough computer nerd to figure this one out. If you have any further advice here I’m all ears. You want system, the latest events, look for a lot of “red” events, occurring recently. is there like a flood of events ? 100 a minute or 1000 an hour or something ? Well check what the latest Red events are , or what the flood is about ---
**Author:** ![Daylate](https://avatars.discourse-cdn.com/v4/letter/d/9dc877/32.png) [@Daylate](https://boards.straightdope.com/u/Daylate)\ **Post date:** [February 26, 2014, 5:33pm UTC](https://boards.straightdope.com/t/computer-interrupts/682195/8 "2014-02-26T17:33:04Z")
I checked the “events” list, and found that there are 17 errors shown in the last seven days. These were: ``` Name # events ``` Windows Update Agent; 7 Atapi; 6 disk 4 Is this significant? ---
**Author:** ![Daylate](https://avatars.discourse-cdn.com/v4/letter/d/9dc877/32.png) [@Daylate](https://boards.straightdope.com/u/Daylate)\ **Post date:** [February 26, 2014, 5:35pm UTC](https://boards.straightdope.com/t/computer-interrupts/682195/9 "2014-02-26T17:35:11Z")
Also, does anyone know why the formatting chosen in writing a message on SD is not preserved after the message is submitted? I really did a neater job of writing the message than it looks like to you guys.