Hyper-V VM failed to start - General access denied errror

VMMS Account does not have sufficient privilege to open attachment ".....\SRVVirt.vhd"

I am logged in as administrator, Services ara running with following accounts :

Hyper-V Image Management Service - Network Service

Hyper-V Networking Management Service - Local System

Hyper-V Virtual machine managemet - Local System

Operating system is clear installation of Windows Server Standard 2008 RTM with Hyper-V

Installed roles :

Application server

File Services

Hyper-V

Web Server

any suggestions on how to overcome this issue and get the hypervisor running would be greatly appreciated.

thanks.

Radek

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