I was having a problem creating some large disk images on my Windows Home Server from my Mac. I thought that the Avast! antivirus could be causing some problems with this. So I decided to try uninstalling it, and seeing if I could create the files. Unfortunately, attempting to uninstall it from the Add-in screen of the Windows Home Server or from the Add/Remove Programs from the Control panel failed.
This post has a some steps that worked for me to uninstall Avast! antivirus. It looks like the disk image creation is also working better without Avast!, so I probably will not reinstall it.