About Contribute Disclaimer Contact News
The information on this site is offered in good faith and no responsibility can be accepted for misuse that leads to loss of data or damaged hardware.
Help Us Improve
Have you spotted an error, or found something confusing or ambiguous? Help us improve our articles......

Google Advert Links
spacer Multibooters.com

An Introduction to Virtual Operating Systems.

virtual globe

In the corporate and business worlds the use of virtualization has changed the way that hardware is being utilized. For the average PC user we can take advantage of a bit of virtual to allow us some dual or multi-booting without having to make any fundamental or potentially risky changes to our computer.

Going Virtual.

There are a couple of ways we can take advantage of virtual and perhaps the easiest is by simply installing a specialist program on our machine that can create the virtual environment where we can install another operating system and use it almost as if we were running it normally. We can literally have two (or more) operating systems running at once that we can switch between and use for different tasks.

We can test and get to know a new operating system while still being able to use our current one. We can use a virtual OS to trial software and updates, or use it for general web surfing, knowing that any problems we cause won't affect our main OS. Or conversely we can use a virtual OS just for sensitive logins and banking etc, keeping private data out of and beyond the reach of our everyday operating system. We can keep a virtual OS where we can continue to use older software and programs that won't work in our new current OS. We can also use virtual as a way to run an operating system that might not easily install on the hardware of our physical machine, for example Windows on a Mac or even vice versa.

Some other benefits of this type of virtual are that an entire operating system is packaged up as a single file, which means it is easy to make copies for backup purposes. We can also configure slightly different versions of our virtual OS that we can save and switch over to when required. Amazingly we can even convert our existing Windows OS to a virtual one so we can run a copy of our operating system inside our operating system, or of course from inside any other suitably configured OS on our machine. And perhaps best of all we can transfer our virtual OSes to other machines that we have installed our virtual system in, which means among other things we can if we have made a virtualized copy of our main and cherished operating system have it live on even after the machine it was born on has died or been retired.

virtual choices

Getting started with virtualization.

At first glance it may seem a little confusing and daunting but once you understand the options and know what to choose, then it really is just a point and click affair. There are a few different virtualization programs you can choose between for PCs but we recommend VirtualBox as being the most rounded and the one you will find the most guides and support for. Here's the link to the documentation and to a few of the better walk-through guides that we have seen, for Windows and Linux.


It's not all upside however as there are a couple of shortcomings to this way of running a virtual operating system. For starters the virtual OS won't have full or exclusive use of a machines physical hardware, with the consequence that performance will be limited and many graphic or processor intensive applications simply may not run. It is also of course completely dependent on the host operating system that it is running in, which means it can't be used as a fallback OS that we can switch to if we suddenly can't get into our primary operating system. Then there is always the possibility that the virtual system itself could end up causing us a problem in our main OS, thereby making it a liability instead of a benefit. Almost any program that we install in our operating system could cause issues or have a conflict with something else on our machine, so adding new programs is never without some risk. You would be well advised to make a fresh backup of your entire operating system, or at the very least create a new restore point just prior to installing whichever virtual system you choose.

Also bare in mind that with Windows a virtual install needs licensing exactly as a physical install does, so you will need a valid product key either at install time, or for later activation. Most of the other OSes we may wish to virtualize can legitimately be used for free, which includes most Linux distros plus Solaris, BSD and several others. While it is possible to virtualize Mac OS X it is not officially sanctioned by Apple, but it seems they are not against it as long as you have a properly purchased copy of their operating system. The results of virtualizing Mac and some others like Android and Chrome can be problematic and are never really practical for real world use and they are definitely not for the novice to be starting with, so we recommend you stick to Windows and Linux until you get your bearings in the virtual world.

Native Virtual Hard Drive -

say what?

native VHDFirst available in just the Ultimate and Enterprise editions of Windows7, the new 'Native Virtual Hard Drive' is a way to run a virtual operating system all on its own without the need for additional emulation software or even a host operating system in which to run it. A Native VHD is essentially a virtual drive that can be installed to and then booted into directly by the Windows bootmanager, thereby giving us a completely standalone virtual operating system that is neither dependent on, nor has to share resources with a host operating system. Someday I'll look into how this magic is achieved, but for now I'll just quietly take what the boffins have given us.

Any version of Windows8 can run 'natively' from such a virtual drive, which means that everyone can now take advantage of this amazing innovation. All that is required is to first create the virtual drive, which entails no more than creating a single VHD file with a few clicks in Windows own Disk Management Utility (from any version of Win7or8). Then we just have to have that file sitting anywhere on our physical hard drive when we reboot our machine from any Win8 install media and after directing setup to use the virtual drive, we carry out a normal and standard Windows installation. The Windows bootmanager will be configured for us and we will get a boot menu at computer startup where we can select to use our original Windows operating system, or our new virtual one.

The standalone and independent nature of this type of virtual operating system means it can remain accessible despite a machine's main OS becoming unbootable. We can also easily make copies of VHD files for backup, or to run clones of the same OS, either on the build machine or on another computer. If we want to return a machine to normal all we have to do is delete the VDH file from the physical hard drive and remove the boot entry in the Windows bootmanager, which takes just a couple of clicks.


Going Native.

The highend versions of Win7 and any version of Win8/8.1 (and presumably any later version of Windows) will boot and run independently from a virtual hard drive. If you already have any standard Win-8 install media such as a DVD or USB key, or even just a downloaded ISO file, then you are good to go and the following guides are the best we have found to show you how. If you don't yet have Win8 then how to download a trial version is also covered.

Unlike when using emulation software we obviously can't run two operating systems at the same time and so it will require a full computer reboot to change from one to the other. There is no nesting of VHDs allowed, so we can't run a virtual OS inside our virtual OS. Also don't expect full performance from a VHD operating system because there will still be some hardware emulation involved. Hibernation won't function in VHDs and both Bitlocker and Dynamic disks can't be used at all, even on the host computer.

A Fixed or a Dynamic VHD?
When creating your VHD file there is an option to either make it a 'fixed' size, or to make it 'dynamic' so that the size of the virtual hard drive will only ever be the size of the data that is within it. A fixed value of 20gig will mean your VHD file will always be 20gig, and a dynamic value of 20gig will mean your VHD file will expand and shrink as required to the size of the data inside it. This can make for a substantially smaller VHD file, which can make it much easier to copy and backup, but it will impact performance a little bit on slower machines as the file is being dynamically resized, plus if you run out of physical hard drive space to hold an expanding VHD file then there is the possibility of data corruption. A fixed size VHD on the other hand has already reserved all the space it requires on the physical hard drive so there is no danger of it being restricted, and no performance lost to dynamic resizing.

The Windows-8 Bootmenu Screen.
The last installed Windows operating system always puts its version of the Windows bootmanager in place, so if you are installing Win8 for the first time then on reboot you will see the new graphical Win8 bootmenu screen. The main reason we now have a graphical boot menu is to provide nice big buttons for touch-screen devices, but it comes at a cost because of course the touch-screen has to be initialized for it all to work, which requires drivers to be loaded and hence we have to wait until Windows is almost fully booted before we are offered a boot menu. This wait for a bootmenu can be bad enough, but if we then choose to boot a different OS to the one that has already been substantially loaded, we have a further wait until this is then shut down and the computer does a reset and a cold reboot into the OS we have chosen. For more on this and how to revert to a simple text based bootmenu that appears immediately, see..info icon Removing the Win-8 Delayed Touch Screen Bootmenu.


Checking for and enabling hardware virtualization support.

The defining factor that makes a virtual operating system virtual is that for the most part it won't be running directly on the real hardware of a machine but on virtual hardware that is being emulated in software. The components that a virtual operating system sees are not those of the real world but of a simulated one that has been created for it. This means a virtual OS will always have less power and resources at its disposal than an OS that is running directly and exclusively on the real physical hardware.

There is something called 'Hardware Assisted Virtualization' that can give a virtual system some support from the real hardware. Even mid range PCs now include some of these hardware technologies in their processors and you should check if your CPU is one of these and most importantly that it has been enabled by being turned on in the firmware (the BIOS or UEFI), of the motherboard.

windows logosMicrosoft® Hardware-Assisted Virtualization Detection Tool.
You can download a small tool from Microsoft that works for both Intel or AMD machines and can tell you if your CPU has the necessary ability and if it is turned on. Here are links to the download page and an offsite guide to using it.info icon Hardware-Assisted Virtualization Detection Tool.

windows logosIntel® Processor Identification Utility.
Intel's own processor identification tool will tell you everything about your CPU, including whether or not it has the desired Virtualization Technologies. info icon Processor Id Utility download for Windows.



up arrowTop of page....
spacermultibooters.com:- March 2014

Google's New Desktop Strategy: Build it straight into Windows by way of Chrome itself. www.infoworld.com

multibooters logo multibooters.com
creative commons licence

All product and company logos, icons and images that are reproduced on this site are the property and trademarks of their respective owners and are used here merely to illustrate their products, NOT to indicate or infer any endorsement or partnership unless otherwise stated. We have endeavored not to reproduce copyrighted images or graphics or infringe upon the rights of any trademark or copyright holder. If you believe or suspect we may have breached the permissible use of copyrighted material then please bring it to our attention. The reproducing or copying of original material from this site is currently allowed for non commercial purposes with the provision that your source is clearly indicated and that a back-link to the referenced information is included. Thank You. See our full  Terms of Use.  Material on this site is not guaranteed to be free of errors.   Multibooters.com   2012 - 2013

Home Sitemap Privacy-Policy About Contact/Feedback Donate Copyright/Legal