The default target device software on the ISO doesnt work with PVS RAM with Disk Overflow…
Download http://support.citrix.com/article/CTX140338 PVS710TargetDeviceWX64002.zip and use this version.
The best is to start all over again with a golden image deployment(SCCM or MDT TS Deployment or RES Wisdom for example). After the deployment is finished install the target device software from the hotfix and capture a new vDisk.
Updating Target device software is a real pain in the !@#. Updating info: http://support.citrix.com/article/CTX135746