I don’t think that virtualization is going to be the answer for you. With the high CPU requirements and the good memory requirements VMware or Virtual PC probably won’t work out best for you.
Many IT schools will setup a Ghost or RIS server then at the beginning of each class week they re-image all the machines with the correct image for that class.
In your case you’d build and store 7 computer images up on the file server. At the beginning of each class usually during the introduction you give each student a floppy disk which they then boot the desktop off and and select the correct software package (based on the file name of the image) to load. It’ll then take about 30-60 minutes to image the machines during which introductions etc and basic concepts can be handled. If the IT staff wants to, then can handle the re-imaging of the machines before hand, but this does require knowing where each person will be sitting.
The key to setting up a good imaging solution like this is very fast disks on the server (as all 60-100 people will be reading a 3-8Gig file from the file server at one time) as well as a very fast network connection from the network switch in the classroom to the network switch in the server room, as well as from the server room network switch to the file server it self. You’ll need several Gig ports or even look into 10 Gig networking between the switches and to the file server.
In addition to a large fast RAID array you’ll want to make sure to select a RAID controller which has as much cache as possible on it.
Another solution is possibly using HP Rapid deployment server or IBM Director software, with this you could basically have your seven images stored ona any form of storage as compressed images, when you need to run a class set a schedule on the firday to run over the wekend with whatever arrangement of different servers is required for the Monday, drag this job to either a single machine or group of machines and off it will go, ghosting is good until you change machines or have a range of different hardware, this method will run through an unattended installtion from go so you will also not have issues with SIDs etc. both methods are vaible (Ghost or RPD/Director), its a mattre of choice at the end of the day.
hope this helps in some way