After deploying Virtual Desktop Infrastructure (VDI) components, the components must first connect to the virtual management servers on your network. Credentials are needed to connect to the virtual servers.
OfficeScan/Core Protection Module VDI needs vCenter 'root' access because some operations may require elevation to be completed. Although this level of access may already be assigned to a certain user, it is always safer to use the root account to ensure uninterrupted operations.