> For the complete documentation index, see [llms.txt](https://pinvokeisalive.gitbook.io/pinvoke/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://pinvokeisalive.gitbook.io/pinvoke/desktopfunctions/kernel32/definedosdevice.md).

# DefineDosDevice

### C# Signature:

```cs
[DllImport("kernel32.dll")]
static extern bool DefineDosDevice(uint dwFlags, string lpDeviceName,
   string lpTargetPath);
```

### Sample Code:

```cs
// Define a virtual drive
VolumeFunctions.DefineDosDevice(0, @"Y:", @"c:\test\folder\name\");

// Delete a virtual drive. The drive letter and folder must match.
VolumeFunctions.DefineDosDevice(
    VolumeFunctions.DDD_REMOVE_DEFINITION + VolumeFunctions.DDD_EXACT_MATCH_ON_REMOVE, 
    @"Y:", 
    @"C:\test\folder\name");

// Delete if you know only the drive letter.
DeleteVolumeMountPoint(@"Y:\");
```

### Sample Code:

```cs
public class VolumeFunctions
{
    [DllImport("kernel32.dll")]
    internal static extern bool DefineDosDevice(uint dwFlags, string lpDeviceName,
    string lpTargetPath);

    [DllImport("Kernel32.dll")]
    internal static extern uint QueryDosDevice(string lpDeviceName,
    string lpTargetPath,uint ucchMax);

    internal const uint DDD_RAW_TARGET_PATH = 0x00000001;
    internal const uint DDD_REMOVE_DEFINITION = 0x00000002;
    internal const uint DDD_EXACT_MATCH_ON_REMOVE = 0x00000004;
    internal const uint DDD_NO_BROADCAST_SYSTEM = 0x00000008; 
}
```