C#: Test if string is a guid without throwing exceptions?

public static Boolean TryStrToGuid(String s, out Guid value)
{
    try
    {
    	value = new Guid(s);
    	return true;
    }
    catch (FormatException)
    {
    	value = Guid.Empty;
    	return false;
    }
}

c:Program Files
c:Program Files.old
c:Users
c:Users.old
c:UserManager.{CE7F5AA5-6832-43FE-BAE1-80D14CD8F666}
c:Windows
c:Windows.old

Catch FormatException:
   10,000 good:     63,668 ticks
   10,000 bad:   6,435,609 ticks

Regex Pre-Screen with try-catch:
   10,000 good:    637,633 ticks
   10,000 bad:     717,894 ticks

COM Interop CLSIDFromString
   10,000 good:    126,120 ticks
   10,000 bad:      23,134 ticks

Catch exception:
   10,000 good:    63,668 ticks
   10,000 bad:  6,435,609 ticks

Regex Pre-Screen:
   10,000 good:   637,633 ticks
   10,000 bad:    717,894 ticks

COM Interop CLSIDFromString
   10,000 good:   126,120 ticks
   10,000 bad:     23,134 ticks

/// <summary>
/// Attempts to convert a string to a guid.
/// </summary>
/// <param name="s">The string to try to convert</param>
/// <param name="value">Upon return will contain the Guid</param>
/// <returns>Returns true if successful, otherwise false</returns>
public static Boolean TryStrToGuid(String s, out Guid value)
{
   //ClsidFromString returns the empty guid for null strings
   if ((s == null) || (s == ""))
   {
      value = Guid.Empty;
      return false;
   }

   int hresult = PInvoke.ObjBase.CLSIDFromString(s, out value);
   if (hresult >= 0)
   {
      return true;
   }
   else
   {
      value = Guid.Empty;
      return false;
   }
}


namespace PInvoke
{
    class ObjBase
    {
    	/// <summary>
    	/// This function converts a string generated by the StringFromCLSID function back into the original class identifier.
    	/// </summary>
    	/// <param name="sz">String that represents the class identifier</param>
    	/// <param name="clsid">On return will contain the class identifier</param>
    	/// <returns>
    	/// Positive or zero if class identifier was obtained successfully
    	/// Negative if the call failed
    	/// </returns>
    	[DllImport("ole32.dll", CharSet = CharSet.Unicode, ExactSpelling = true, PreserveSig = true)]
    	public static extern int CLSIDFromString(string sz, out Guid clsid);
    }
}

new Guid(someString);

Exception:    26ms
Interop:   1,201ms

Exception: 1,150ms
  Interop: 1,201ms

try
{
  value = new Guid(s);
  return true;
}
catch (FormatException)
{
  value = Guid.Empty;
  return false;
}

^[A-Fa-f0-9]{32}$|^({|\()?[A-Fa-f0-9]{8}-([A-Fa-f0-9]{4}-){3}[A-Fa-f0-9]{12}(}|\))?$|^({)?[0xA-Fa-f0-9]{3,10}(, {0,1}[0xA-Fa-f0-9]{3,6}){2}, {0,1}({)([0xA-Fa-f0-9]{3,4}, {0,1}){7}[0xA-Fa-f0-9]{3,4}(}})$

using System.Text.RegularExpressions;


 /// <summary>
  /// Validate that a string is a valid GUID
  /// </summary>
  /// <param name="GUIDCheck"></param>
  /// <returns></returns>
  private bool IsValidGUID(string GUIDCheck)
  {
   if (!string.IsNullOrEmpty(GUIDCheck))
   {
    return new Regex(@"^({{0,1}([0-9a-fA-F]){8}-([0-9a-fA-F]){4}-([0-9a-fA-F]){4}-([0-9a-fA-F]){4}-([0-9a-fA-F]){12}}{0,1})$").IsMatch(GUIDCheck);
   }
   return false;
  }

public static Boolean TryStrToGuid(String s, out Guid value)
{

     // this is before the overhead of setting up the try/catch block.
     if(value == null || value.Length != 36)
     {
        value = Guid.Empty;
        return false;
     }

    try
    {
        value = new Guid(s);
        return true;
    }
    catch (FormatException)
    {
        value = Guid.Empty;
        return false;
    }
}

public static string IsValidGuid(string str)
{
    Guid guid;
    return Guid.TryParse(str, out guid);
}

bool IsProbablyGuid(string s)
    {
        int hexchars = 0;
        foreach(character c in string s)
        {
           if(IsValidHexChar(c))
               hexchars++;
        }
        return hexchars==32;
    }

Private Function IsGuidWithOptionalBraces(ByRef strValue As String) As Boolean
    If String.IsNullOrEmpty(strValue) Then
        Return False
    End If

    Return System.Text.RegularExpressions.Regex.IsMatch(strValue, "^[{]?[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}[}]?$", System.Text.RegularExpressions.RegexOptions.IgnoreCase)
End Function


Private Function IsGuidWithoutBraces(ByRef strValue As String) As Boolean
    If String.IsNullOrEmpty(strValue) Then
        Return False
    End If

    Return System.Text.RegularExpressions.Regex.IsMatch(strValue, "^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}$", System.Text.RegularExpressions.RegexOptions.IgnoreCase)
End Function


Private Function IsGuidWithBraces(ByRef strValue As String) As Boolean
    If String.IsNullOrEmpty(strValue) Then
        Return False
    End If

    Return System.Text.RegularExpressions.Regex.IsMatch(strValue, "^{[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}}$", System.Text.RegularExpressions.RegexOptions.IgnoreCase)
End Function