3 Hidden Features In Firefox 15 You May Want To Enable

Firefox 15, which has been released a few days ago, comes with some cool features disabled by default: native PDF viewer, preferences in tab and click-to-play plugins.
These features have been in testing for quite a while, but they are not 100% ready so they aren’t enabled by default and there are no options in the Firefox preferences to enable them. But, if you don’t mind an occasional glitch, you can enable them  using the about:config tool.

firefox 15 native pdf reader pdf.js


Firefox 15 comes with a native PDF reader that uses JavaScript (pdf.js) to open PDF files directly in the browser. This feature is disabled by default but it can be enabled by following these steps: open a new tab, type “about:config”, search for “pdfjs.disabled” and set it to “false” (double click it).
firefox 15 preferences in tabs


In Firefox 15, you can also enable ‘preferences in content’ which makes the Preferences window open in a new tab instead of using a new window. To enable this, type “about:config” in a new tab, search for “browser.preferences.InContent” and set it to “true” (double click it).
firefox 15 click to play plugins


And the third hidden feature in Firefox 15 is “click-to-play” plugins, which disables plugins like Adobe Flash by default but you can still play them with a single click. This prevents Flash and other plugins from loading automatically. To enable ‘click-to-play plugins’ in Firefox 15, type “about:config” in the address bar, search for “plugins.click_to_play” and set it to “true“.

Note: after changing the native PDF reader and click-to-play plugins preferences in about:config, you need to restart Firefox for the changes to take effect.

Reinstall / Recover GRUB from Ubuntu live CD / USB

After installing Windows / Fedora your Ubuntu will not boot anymore and its grub may be wiped out. To restore it follow the steps below.

To Reinstall Grub

You need to have Ubuntu Live CD or Live USB. Normal session can be used to repair the grub. Boot using your Ubuntu Live CD or Live USB, while booting choose Try Ubuntu.

Once booted then open a terminal, and run the following command one by one to install the boot repair.

To add boot-repair to the repository,just add below two lines to “/etc/apt/sources.list”  according to your Ubuntu version:

Ubuntu 13.04:

deb http://ppa.launchpad.net/yannubuntu/boot-repair/ubuntu raring main
deb-src http://ppa.launchpad.net/yannubuntu/boot-repair/ubuntu raring main

Ubuntu 12.10:
deb http://ppa.launchpad.net/yannubuntu/boot-repair/ubuntu quantal main
deb-src http://ppa.launchpad.net/yannubuntu/boot-repair/ubuntu quantal main

Ubuntu 12.04:

deb http://ppa.launchpad.net/yannubuntu/boot-repair/ubuntu precise main
deb-src http://ppa.launchpad.net/yannubuntu/boot-repair/ubuntu precise main

To Update your repository

$ sudo apt-get update

To install boot-repair

$ sudo apt-get install -y boot-repair

Once Installation complete run boot-repair on terminal by typing the following command or select it by

System->Aministration->Boot Repair.

$ boot-repair

NOTE: Update the Boot Repair if its newer version is available.

It will scan the System for few seconds and will show you the options Recommended repair and Create a BootInfo summary. By clicking the Recommended Repair it will start repair the grub. Check the screen shots below.

Once done click ok and restart your system, your grub should work now. If not run the boot-repair again using live cd / usb. Then follow the steps below.

Select the Advanced options, In Main options tab check whether the following options are selected or not. If not select it, the options are Reinstall Grub and unhide boot menu for 10 seconds. Check the screen shot below

Then select the GRUB locations tab and check the following options are selected or not. The options are OS to boot by default and place grub into, In “OS to boot by default” option choose the OS which you want to be default on boot. Then select the drive where you need to reinstall the grub in “place grub into” option and click apply. Check the screen shots below

Click ok and restart your System.