How can I get a new browser session when opening a new tab or window on Firefox/Chrome?

Whenever I click a link from something like outlook or a program opens a web page (not when I click a link from within chrome). It opens up in Chrome since it is my default browser but if I already have a page open it will open in a new tab on that same window. I can't tell you how many times I forget about this and close the window out, accidentally losing the other tab too. Ofcourse, I can open a new chrome window and find it under recently closed tabs but I would really just prefer if they opened in their own window so I can prevent this.

There doesn't appear to be a user-friendly option to change this inside Chrome (presumably because most people prefer the new tab).

However, you can change this manually by editing the command specified in your Windows registry used to open an http url.

To do this, open regedit and:

1. Go to HKEY_CLASSES_ROOT\http\shell\open\command
2. You should see one key, named (Default). Double click this to get an editing popup.
3. At the end of the Value data: field you should see the text -- "%1". Change this to --new-window "%1".

That will instruct Windows to open all http links in a new window of Chrome instead of a new tab.

Presumably, the same general idea is true for Mac and Linux, but I don't know offhand where they store the command to open urls.

Problem
For Linux, if you have multiple VNC servers, this same problem will occur.
That is,

$ google-chrome
Created new window in existing browser session

And no google chrome window will appear in the current X VNC session (a new tab will appear in the X session with the first instance of google-chrome).

Solution
A simple workaround is to run

$ google-chrome "--user-data-dir=${HOME}/.google-chrome/session${DISPLAY}"

This sets a unique user directory based on the X VNC instance in use. The user directory will be created as needed. The new google-chrome process will display within the current X VNC session.

Mike Hardy posted a solution for Mac OS X. I'm using it in 10.7 Lion and it works fine.

The solution involves a small AppleScript application:

on open location theURL
    tell application "/Applications/Google Chrome.app"
        make new window
        activate
        set URL of active tab of first window to theURL
    end tell
end open location

Setting this application as your default browser will cause external program links to open in a new window in Chrome.

In case any Linux users are wondering the same thing, I did this by copying /usr/share/applications/chromium.desktop to ~/.local/share/applications and then editing it as follows:

--- /usr/share/applications/chromium.desktop    2012-08-10 17:02:01.000000000 +0100
+++ /home/sam/.local/share/applications/chromium.desktop    2012-08-23  10:33:21.987359591 +0100
@@ -128,7 +128,7 @@
 Comment[zh_CN]=访问互联网
 Comment[zh_HK]=連線到網際網路
 Comment[zh_TW]=連線到網際網路
-Exec=/usr/bin/chromium %U
+Exec=/usr/bin/chromium --new-window %U
 Terminal=false
 X-MultipleArgs=false
 Type=Application

If you're using the Debian chromium package, and you don't mind setting this as the default for all users on the system, you can instead edit /etc/chromium/default and add --new-window to the CHROMIUM_FLAGS variable.

You can use the "New Tab, New Window" extension for this. They way it works is moving the newly created tab quickly to a new window. So there is a bit of redrawing, but it does work pretty well (for me at least).

Note, as @John mentions below, this extension makes the default behavior for all new tabs (even ones created from inside Chrome).

With a Macbook and Chrome browser, this extension works great for opening a new window and NOT opening a tab:

https://chrome.google.com/webstore/detail/new-tab-new-window/dndlcbaomdoggooaficldplkcmkfpgff