When you use System Center 2012 R2 Virtual Machine Manager (VMM R2) to provision a physical computer as a virtual machine host (also known as bare-metal deployment), it may take longer than expected to install matching device drivers.
Changes to the driver file-copy process in VMM R2 trigger multiple polling activities per file, and this may increase the transfer time per file. The more files that are included in the file-copy operation, the more noticeable this symptom is.
This is a known issue in System Center 2012 R2 Virtual Machine Manager. A fix for this issue is scheduled for inclusion in a future update.
To work around this issue, reduce the number of driver packages that you're deploying to a minimum number of files. This may involve configuring the physical computer profile by setting the driver filter to Filter drivers with matching PnP IDs. By doing this, you make sure that only those drivers that match the Plug and Play (PnP) IDs on the target physical computer are used.
For more information about configuring the physical computer profile, see the following TechNet article: