How to disable VirtualStore for C++ programs?

Question

I'd like my program to throw an error when it tries to create files in protected locations like the root of the C:\ drive (eg: FILE* FileHandle = fopen("\\file.txt", a)). Instead the file gets created in the Virtual Store under %APPDATA%.

How can I disable that Virtual Store?

Thanks

EDIT: Just to be clear, I'm not asking how to circumvent the security and create my file in a protected location. I want the file creation to FAIL so that I can tell the user he was an idiot.

Answer 1

You add an application manifest. Choose asInvoker, highestAvailable, or requireAdministrator. It sounds like you want asInvoker.

From http://msdn.microsoft.com/en-us/library/bb756929.aspx:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0"> 
  <assemblyIdentity version="1.0.0.0"
     processorArchitecture="X86"
     name="IsUserAdmin"
     type="win32"/> 
  <description>Description of your application</description> 
  <!-- Identify the application security requirements. -->
  <trustInfo xmlns="urn:schemas-microsoft-com:asm.v2">
    <security>
      <requestedPrivileges>
        <requestedExecutionLevel
          level="asInvoker"
          uiAccess="false"/>
        </requestedPrivileges>
       </security>
  </trustInfo>
</assembly>

Answer 2

From MSDN:

Virtualization is only enabled for:

• 32 bit interactive processes
• Administrator writeable file/folder and registry keys

Virtualization is disabled for:

• 64 bit processes
• Non-interactive processes
• Processes that impersonate
• Kernel mode callers
• Executables that have a requestedExecutionLevel

Your best bet, as Adam Maras noted, is to set a requestedExecutionLevel on your application by adding a manifest. A requestedExecutionLevel of "asInvoker" will cause file operations to fail on protected locations, rather than redirecting to the virtual store or prompting for elevation.

Answer 3

Here is an article that shows how to turn off the virtualization.

http://www.interworks.com/blogs/dsmith/2011/09/21/disabling-windows-7-virtual-store

The short of it is:

-From the Windows 7 Start Orb, do a search for Local Security Policy and select it.

-Expand Local Policies and click on Security Options. On the right pane, scroll all the way to the bottom and you will find a setting called " User Account Control: Virtualize file and registry write failures to per-user locations", double click on that setting and change it to Disabled.