Well I hope your issue was fixed but I would have thought that you need a Windows vps and not a linux one if you plan to use Windows. Maybe the linux vps doesn't have the features required to run Windows. The Windows vps usually comes with more memory and hard drive space because Windows require more of those resources than linux.
Windows uses more memory/resources than linux, but the slice level is the same. Now KVM has a choice to select Ubuntu 14.04 Desktop which comes with XRDP and XFCE desktop environment. It uses a low amount of memory and gives remote desktop and a gui. Firefox is preinstalled.