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Can IE 9 be installed side-by-side with IE 8? If not what are some recommendations for using IE9 for testing?

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migrated from Sep 16 '10 at 1:55

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No. As with previous IE beta releases, the new IE9 beta completely replaces the integrated IE8. IE9 can emulate IE8 using EmulateIE=8 but it's not guaranteed to behave in exactly the same way.

There will probably be multiple-IE hacks that can be adapted for IE9, but again they've never quite exactly reproduced the behaviour of previous browsers. The fully reliable way to emulate previous browser releases is still to use a virtual machine.

The IE9 ‘platform preview’ is different, it's a stand-alone application (and far from a full browser).

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Similar to IE7 and IE6 testing along IE8, virtual machines are especially useful. However, there are some tools that test only the rendering portion of IE (Trident) that can run a page against the different versions concurrently, but some other non-rendering bugs could remain.


Microsoft Expression Web SuperPreview:


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You could use to sandbox the browser. It requires a browser plugin for your current browser though

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I can see there are two main reasons for asking this question:

Reason 1) You don't want your machine to screw up if there are bugs

  • TOUGH LUCK! If it crashes it crashes - but fingers crossed it's a good quality beta.


  • Run it in a VM

Reason 2) You want to test your website on IE8 and IE9

  • You can change compatibility settings through the F12 developer tools.

    Just hit F12 and click the Browser Mode button at the top to select which compatibility mode you want. I'm not exactly what the 'end user friendly' compatibility mode does, but this is the setting you should change as a web developer.

  • You should probably run a VM if it is really critical - or use a second machine

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I have installed IE9 on a machine that already had IE8 installed, and both work although I don't use IE extensively; My primary browser is Chrome.

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seriously? How does this look like? IE8 exists there and IE9 beta also? – mare Sep 15 '10 at 22:39
This was definitely possible with the IE9 platform preview builds, but I dont know if the IE9 beta released today supports a side-by-side install next to IE8. – David Sep 15 '10 at 23:24
according to the folks at microsoft that's a big no – Buildstarted Sep 15 '10 at 23:29

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