15 Windows 7 virtual machines, server specs suggestions pls

[Trust_words]

Hi,
I am planning budget for a computer lab in a k-12 school. I am trying to find the cheapest yet stable solution possible so I thought of Virtualization as an option but I need your help on this.
The computer lab is for 15-20 PCs(students). So what are the MINIMUM specs needed for the server to run those 20 Windows 7 virtual machines smoothly?

The systems are not supposed to include heavy applications. The heaviest one I can think of is MS Office 2010. Its to teach kids how to use computers and browse internet thats all.
Which one you recommend as a host system? Windows or Linux? I have experience on both..

I have run up to 4 virtual machines in the past but don't remember the specs I needed to do that. And I never ran more than that on one machine.

Any help is appreciated
Thank you

[bmrey]

This is taken straight from Microsoft documentation...


Windows 7 system requirements
If you want to run Windows 7 on your PC, here's what it takes:

1 gigahertz (GHz) or faster 32-bit (x86) or 64-bit (x64) processor

1 gigabyte (GB) RAM (32-bit) or 2 GB RAM (64-bit)

16 GB available hard disk space (32-bit) or 20 GB (64-bit)

DirectX 9 graphics device with WDDM 1.0 or higher driver

http://windows.microsoft.com/is-IS/wind ... quirements

So if we take that as what Microsoft recommends I would say something close to 20GB of RAM or more depending if you want to also run Windows 7 with Areo enabled and which version of Windows you are going to use.. That is not including the RAM for Windows/Linux for the Host to run the guest OS.

Minimum for Hard drive space is 400 GB.

Hope this helps as a start.