Yep, "Fonts" and "fonts" are the same in Windows...  But, it wouldn't be to
hard to code a method to do this.  Yanking the FindFirstFile prototypes and
structures from some of Stephen Toub's articles [1][2] and throwing together
a loop:
/// <summary>
/// Get the actual path case-correct for <paramref name="path"/>
/// </summary>
/// <author>Peter Ritchie</author>
/// <param name="path"></param>
/// <returns>Actual Path</returns>
/// <exception cref="T:System.Security.SecurityException">The caller does
not have the required permissions. </exception>
/// <exception cref="T:System.ArgumentNullException">path is null.
</exception>
/// <exception cref="T:System.ArgumentException">path is a zero-length
string, contains only white space, or contains one or more invalid characters
as defined by <see cref="F:Path.InvalidPathChars"></see>, or contains a
wildcard character.-or- The system could not retrieve the absolute path.
</exception>
/// <exception cref="T:System.NotSupportedException">path contains a colon
(":"). </exception>
/// <exception cref="T:PathTooLongException">The specified path, file name,
or both exceed the system-defined maximum length. For example, on
Windows-based platforms, paths must be less than 248 characters, and file
names must be less than 260 characters. </exception>
/// <exception cref="T:System.ArgumentException">The path parameter contains
invalid characters, is empty, or contains only white spaces, or contains a
wildcard character. </exception>
/// <using>
///    using System.IO;
///    using Microsoft.Win32.SafeHandles;
///    using System.Security.Permissions;
///    using System.Runtime.ConstrainedExecution;
/// </using>
static String GetPathActual ( String path )
{
    String result = "";
    path = Path.GetFullPath(path);
    Win32Native.WIN32_FIND_DATA findData = new Win32Native.WIN32_FIND_DATA();
    if (File.Exists(path))
    {
        Win32Native.FindFirstFile(path, findData);
        result = findData.fileName;
        path = Path.GetDirectoryName(path);
    }
    DirectoryInfo directoryInfo = new DirectoryInfo(path);
    while(Directory.Exists(path) && directoryInfo.Root.Name != path)
    {
        Win32Native.FindFirstFile(path, findData);
        result = findData.fileName + Path.DirectorySeparatorChar + result;
        System.Diagnostics.Debug.WriteLine(path);
        path = Path.GetDirectoryName(path);
        directoryInfo = new DirectoryInfo(path);
    }
    return path + result;
}

internal sealed class SafeFindHandle : SafeHandleZeroOrMinusOneIsInvalid
{
    [SecurityPermission(SecurityAction.LinkDemand, UnmanagedCode = true)]
    private SafeFindHandle ( ) : base(true)
    {
    }

    protected override bool ReleaseHandle ( )
    {
        return FindClose(this.handle);
    }

    [DllImport("kernel32.dll")]
    [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
    private static extern bool FindClose ( IntPtr handle );
}

[System.Security.SuppressUnmanagedCodeSecurity]
internal static class Win32Native
{
    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
    public class WIN32_FIND_DATA
    {
        public int fileAttributes = 0;
        // creationTime was an embedded FILETIME structure.
        public int creationTime_lowDateTime = 0;
        public int creationTime_highDateTime = 0;
        // lastAccessTime was an embedded FILETIME structure.
        public int lastAccessTime_lowDateTime = 0;
        public int lastAccessTime_highDateTime = 0;
        // lastWriteTime was an embedded FILETIME structure.
        public int lastWriteTime_lowDateTime = 0;
        public int lastWriteTime_highDateTime = 0;
        public int nFileSizeHigh = 0;
        public int nFileSizeLow = 0;
        public int dwReserved0 = 0;
        public int dwReserved1 = 0;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 256)]
        public String fileName = null;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 14)]
        public String alternateFileName = null;
    }
    [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    internal static extern SafeFindHandle FindFirstFile ( string lpFileName,
        [In, Out, MarshalAs(UnmanagedType.LPStruct)]
       WIN32_FIND_DATA lpFindFileData );
}

[1] http://msdn.microsoft.com/msdnmag/issues/05/12/NETMatters
[2] http://msdn.microsoft.com/msdnmag/issues/05/10/Reliability 

But what if it's a drive that is mapped to a linux share?