Try this:
Run > type in ..... gpedit.msc > User Configuration > Administrative Templates > Windows Components > Windows Explorer.
In the right hand pane, find “Windows Explorer’s default context menu”, open its properties by double clicking it.
If it’s enabled or not configured, disable it and your context menu will be back as soon as you apply this policy.
With a bit of luck your right click may work now.
If gpedit.msc doesn't do anything ..... you can do this from the registry.
Run > type in ..... regedit > click the > next to the following .....
HKEY_CURRENT_USER > Software > Microsoft > Windows > CurrentVersion > Policies > Explorer.
In the right hand pane find “NoViewContextMenu”, set its value to 0 if it exists
You do this by highlighting it and go to the EDIT in the toolbar > Modify
Change the 1 to a 0