You may receive "Insufficient Privileges" error when you try to deploy VNC to a remote computer or use remote management tools. This error can be caused by incorrect Security configuration. Please try the steps below to check settings:

1. On problem clients, run "gpedit.msc", navigate to:
   [Check Computer Config/Windows Settings/Security Settings/Local Policies/User Rights Assignments]
2. Find "Replace a process level token", add the following account to the list if they are not listed.
   SYSTEM
   Local Service
   Network Service
3. Check if the issue was resolved. If not, add above accounts to "Adjust Memory Quotas for Process Properties"

Source: social.technet.microsoft.com/forums/