How to setup multiple VPS or virtual machines on a VPS hosting account? [closed]

Please consider using dedicated server for your requirements.

Inside of virtual machines the virtual CPU will not have a virtualization instruction. Therefore most of virtualization software will be running very slowly or maybe unable to run.

This is definitely a dedicated server feature, if you really want to do this please consider buying/renting a dedicated server, or getting several VPS's for your need.

Well you can install Xen on your linux vps and create new vps'en with it. But I dont think you can create a windows vps in a virtual Xen. The performance of every vps you make within the vps would be very bad.

So it's possible but it would be the worst thing you can do. You could also get in trouble with your provider by doing this because you're going to create a lot of load and disk I/O

Better is getting a new vps then you get the best performance and a vps isnt expensive.