After today’s Virtualisation Hour there was a lot of buzz surrounding the announcements Microsoft made about memory and naturally XP Mode. I wanted to take a minute though and look more closely at the XP Mode story and hope to help you more clearly understand it.
XP Mode…First off, what exactly is it? Well, it’s virtualisation functionality that allows your Windows 7 machine to run legacy Windows XP applications. Subjectively looking at it, what it does is allows you to migrate to Windows 7 while still having “backwards compatibility” with older, potentially legacy XP apps. Maybe you’ve got an app that was developed a long time ago and the developer left…Maybe you’ve got an app that is being developed for Windows 7 but in the interim you need to support it on XP…Maybe you’ve got an app that is part of a merger or set of existing apps that needs deprecated. XP Mode serves the needs of all of the aforementioned.
XP Mode, however, when it first came out, required what is known as HAV or Hardware Assisted Virtualisation. In the Intel world it’s Intel VT, in the AMD world it’s called AMD-V. Essentially it was a BIOS switch you needed to flip in order to ensure that your hardware could run the virtualisation stack more seamlessly. If you’ve done any 64 bit virtualisation before, surely you’ll have seen this setting. However, the draw back of this meant that the value sell proposition of Windows 7 was less attractive. One of the main benefits of Windows 7 was that it didn’t require all of the resources previous operating systems did and hence you could easily upgrade your older hardware to Windows 7.
However, if you were to upgrade legacy hardware, what did this mean? You guessed it, no Intel VT or AMD-V in most cases, which also now meant no XP mode. With today’s announcement however, you can now virtualise XP without needing HAV.
This gives you a seamless experience and supportability for those legacy XP apps on any piece of hardware. That’s the good news. Here’s the IT spin on it though and where most people go wrong or don’t think of the consequences…
Windows XP mode is a STOP GAP. It is not an enterprise solution. Just because you know certain apps work fine on XP and they don’t pass the acidity test to run on Windows 7 DOES NOT mean simply roll out XP mode. XP mode in a sense is a stand alone machine that is isolated from everything. Now you ask, wait, it’s part of the domain surely? Well, yes, however it only gets fired up by the end user when it is needed, therefore the manageability factor of this workstation is VERY difficult to handle. Let us also not forget that XP SP2 is going End of Life on July 13, 2010.
Also, as an IT admin, ask yourself (if you know about .vhd technology), do you really want .vhd’s floating around in your environment with potentially lucrative company data and applications? Also, each time you rebuild a workstation, now not only is it one rebuild, it’s two – per workstation!
Sure there are times in an enterprise when you need “XP Mode” but there are much nicer enterprise tools available…Take for example MED-V. Alternatively, you could always try to run the app in App-V which would centralise it and make updating much easier and put less overhead and burden on your network. There is further, the option of RDS, but that’s a lot of infrastructure to just support one app.
My point is that while, yes, it is nice to see the XP Mode caveat of HAV taken away, take it with a grain of salt. Play your legacy Flight Sim games at home in XP Mode…Use Microsoft BOB in XP Mode, but please don’t take this announcement to mean that now you have a get-out-of-jail-free card to go deploying XP Mode in your corporate environment.
So, without further adieu, here are the distributables you need to make this happen should you wish to remove the requirement for HAV, making XP Mode work in Windows 7.
and, should you want some more bedtime reading, here is the KB article which corresponds to the announcement and the MSU’s above.