We have great tools to install Windows in a virtual machine. The lab folks that set this all up really know how to be an admin on Windows and have created a system that, on my machine, can get a Windows installation done, unattended, in a VM in about 20 minutes. Normally, this is a big timesaver for us. If you need a Turkish build of Windows 7, just kick off an install, go about other work while setup runs, and in 20 minutes you are ready to test.
But there are some kinks to this. I typically will install a Windows machine and once it is done, make a snapshot of it while it is in a clean state. Reverting to that clean state takes seconds instead of the 20 minutes installation takes. The problems come up when my password changes, which is just did. At this point, I restore the image but cannot access anything on our domain until I log in again. This adds a minute or so while I do that.
Depending on the time stamp of when the machine was last on the network, the machine account can get removed. A restart at a minimum is needed, but often I have to quit and rejoin the machine to the domain. This still takes only a few minutes, but it is "hand's on" time and not something I can walk away from.
So at this point, I usually just delete the old image and start the Windows machine over. That takes a few minutes per image and I have about 14 different VMs that I have been using. At 4 minutes per image, that can take an hour, plus the time goes up as the hard drives start getting thrashed from this.
Reinstalls take 20 minutes each, but I only started with 4 images (English, Thai, German and Russian, x86 and x64). That took just over an hour to get them all installed, again, the hard drives were the limiting factor here.
Once all that was done, I snapshotted them.
This took most of a morning. And then I was ready to start installing builds of Office to test. That took about another hour.
So the day was mostly spent running setup. Each individual task did not take much time, but once you aggregate all of the time needed for each step, what seems simple ("Just install the build and test this fix") can take several hours.
It happens every now and then but is much faster than installing on native hardware.
Questions, comments, concerns and criticisms always welcome,