Virtualization: One CPU Two users at same time?

1. yes and no. You can use it to run a virtual machine, but it isn't quite the way you think it is.

2. no, not this way, I'll elaborate below.

3. yes, actually quite easy

OK, what I think you're aiming for can be done with virtualization, but it will be tricky. VMWare Player, Virtual PC, or Hyper-V can be used to create a second virtual PC that can run on the same machine but be a different machine. The downside is that this is like a simulator game. It will be on the same keyboard, mouse, and monitor as you main PC.

To get a separate workstation that someone can use at the same time, you'd have to set it up with Virtual PC or Hyper-V. (depending on which version of Windows you are using. Windows Vista or 7 use Virtual PC while Windows 8 and 8.1 use Hyper-V. Both are free and from Microsoft, mostly built into the OS. You just need to install the final components.) Set up a virtual machine with a bridged network connection, and the other person can remote into it from an external client. Clients can be a low end laptop, a "thin client" machine, or a tablet. Microsoft makes a remote desktop app for Android, and Windows RT has one built in. the iPad has an app for that, but I believe it is a pay app, not free.

If you use certain products from VMWare, like ESXi hypervisor, you'd need remote clients for both users, as the host machine wouldn't have a direct output console at all. The direct output of the machine would just be a basic management console. VMWare player only works with VMs using a NAT networking structure, and you would not be able to access it remotely.

The cost of the client may make it less feasible to do this. Also, a virtual machine doesn't perform as well as the host machine. Games perform horribly on virtual machines, unless it's a really old game running on a really old operating system. It could run something like Warcraft 2 or Doom, but not something newer like World of Warcraft.

Mostly, virtualization is used for things like running non-graphics oriented programs that aren't supported on a newer operating system, running simulation computers for training, or, in a large company, dividing up resources into many smaller systems to make better use of physical resources.

I'm a systems admin in a test lab. My main uses for virtualization is running infrastructure servers (DNS, DHCP, WDS) for the lab, running remote workstations for remote users to be able to use local resources, and specialized programs for managing the local systems, switches, and storage. I used virtualization in the past to practice and utilize server operating systems for certification training.

There were systems once that could do what you're proposing, but they were either really old operating systems like VMS and Unix, or really high end systems like NeXT.

OK, since you have Windows 8.1, you'd be using Hyper-V.

http/blogs.technet.com/b/canitpro/archive/2014/03/11/step-by-step-enabling-hyper-v-for-use-on-windows-8-1.aspx

Then you create the new VM

http/technet.microsoft.com/en-us/library/cc772480.aspx

Then you install the OS just like you would a regular Windows 8 install, but on the VM instead of the main machine.

http/technet.microsoft.com/en-us/library/cc742460.aspx

Once created and installed, the VM will have a totally separate IP address. You will have to enable the remote desktop connection before someone else can remote into it.

I've done many VMs for many different reasons, but I'm a techie. I have Linux VMs for surfing the internet on places I don't trust. I have Windows 98 and XP VMs for running old programs, like Warcraft 2 and Civilization. I have a VM host specifically for installing Windows Server so I can practice and try new things and gain experience. And, yes, I have even created VMs for other people to use as remote workstations. I've been using them for about 15 years now.

It'll take someone with no virtualization experience a bit of practice to do, but learning it is worth it. Even if you don't make a career of it, learning how to work with it makes your computer skills take a quantum leap in flexibility.