I remember that Unix (Sun blades and Linux) did launch java apps instantly, especially if we compare to Windows. This was cool but now I call a java utility millions of times per second in the batch file and the startup time is the bottleneck. I see that experts exchange have the same question and discovered the option,

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but it is disabled and they have no answer.

  • 2
    I wonder if disk speed is an issue, running the program off a ram-drive might help – Journeyman Geek Oct 7 '13 at 15:26
up vote 2 down vote accepted

For more information I would see this JQS help article


JQS is enabled by default in Windows XP and Windows 2000 operating systems and JQS is not necessary on Windows Vista or Windows 7 as both offer their own pre-loading mechanisms. A process called jqs.exe will run in the background in order to allow quick startup. jqs.exe will be loaded after a Windows restart. Instructions on how to disable the JQS and the jqs.exe process are below.

As far as I can tell, Oracle sees no need for it on Vista and 7. I don't believe it's possible to enable it on either OS. Interestingly enough, the help page provides documentation on how to turn JQS off on Windows 7/Vista, but not on.

As for Vista/7's pre-loading mechanism, it appears that, unfortunately, there's no way to specify programs to cache. It's all done automatically.

As for ramdisks, as Journeyman Geek mentioned, there are tons of options such as AMD Ramdisk or Dataram's Ramdisk.

  • "Their own pre-loading mechanisms" includes Superfetch, which attempts to pre-load files based on predictions from past behavior. – Andy Thomas May 7 '15 at 16:37

I found the method to enable this on any operating system.

Below are the steps. Please modify the paths as per your operating system

  1. Open cmd as administrator

  2. cd C:\Program Files\Java\jre7\bin

  3. jqs.exe -register

  4. jqs.exe -enable

  • I have no jqs.exe. Why should it work better than the option, grayed out in the Control Panel? – Val Jan 27 '14 at 11:21
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    @Val: where are you looking for jqs.exe . It must be inside C:\Program Files\Java\jre7\bin. (modify path accordingly) – Aditya Feb 14 '14 at 8:25
  • You seem not to notice that we already have the answer and what you say contradicts to it. Instead of elaborating, how your solution is better, you invite me to do some magic. I am talking about Windows 7 here and I do not have such folder. – Val Feb 14 '14 at 12:00
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    Ok, I saw that there is already an answer to it, but what I stated is to forcefully turn on jqs.exe in Windows 7. There must be a jre installation folder, and I specified to look for the appropriate path according to the operating system, though I referred the path on Windows 7. I dont find my answer contradicting in any way. The answer(marked as answer) stated that "Oracle sees no need for it on Vista and 7. I don't believe it's possible to enable it on either OS." That doesn't mean oracle has not provided the provision. And also the user(who posted the answer) just says "I believe". – Aditya Feb 26 '14 at 8:06

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