KVM: Windows VM Slowness using UAC

I'm using KVM to host a Windows 2008 R2 server. The VM has 8GB of memory and is using 4 CPUs. When accessing any Windows menu that uses UAC (User Account Control), the VM takes a considerable amount of time to load the window (approximately 1-2 minutes). For example if I go to START > right click Computer > click on "Manage," the VM sits there unresponsive for 1-2 minutes and then prompts me for UAC credentials or acknowledgement.

I've loaded the para-virtualization drivers that were giving errors in Device Manager, but this didn't seem to help. Any idea on how to fix this issue?