HKEY_CLASSES_ROOT\CLSID 包含系统上所有已注册的 COM 文件（.ocx、.dll、.ax）的列表，无论是 32 位还是 64 位。
CLSID 下的键由每个 COM 生成的 GUID 表示。
最后进入 GUID 键，有 InprocServer32 子键，在其中，默认值包含 COM 文件进入系统的路径，因此您可以找到它，如下所示：
VB代码：
''' <summary>
''' Search and Find Registry Function
''' </summary>
Public Shared Function SearchRegistry(ByVal dllName As String) As String
'Open the HKEY_CLASSES_ROOT\CLSID which contains the list of all registered COM files (.ocx,.dll, .ax)
'on the system no matters if is 32 or 64 bits.
Dim t_clsidKey As RegistryKey = Registry.ClassesRoot.OpenSubKey("CLSID")
'Get all the sub keys it contains, wich are the generated GUID of each COM.
For Each subKey In t_clsidKey.GetSubKeyNames.ToList
'For each CLSID\GUID key we get the InProcServer32 sub-key .
Dim t_clsidSubKey As RegistryKey = Registry.ClassesRoot.OpenSubKey("CLSID\" & subKey & "\InProcServer32")
If Not t_clsidSubKey Is Nothing Then
'in the case InProcServer32 exist we get the default value wich contains the path of the COM file.
Dim t_valueName As String = (From value In t_clsidSubKey.GetValueNames() Where value = "")(0).ToString
'Now gets the value.
Dim t_value As String = t_clsidSubKey.GetValue(t_valueName).ToString
'And finaly if the value ends with the name of the dll (include .dll) we return it
If t_value.EndsWith(dllName) Then
Return t_value
End If
End If
Next
'if not exist, return nothing
Return Nothing
End Function
C#代码：
/// <summary>
/// Search and Find Registry Function
/// </summary>
public static string SearchRegistry(string dllName)
{
//Open the HKEY_CLASSES_ROOT\CLSID which contains the list of all registered COM files (.ocx,.dll, .ax)
//on the system no matters if is 32 or 64 bits.
RegistryKey t_clsidKey = Registry.ClassesRoot.OpenSubKey("CLSID");
//Get all the sub keys it contains, wich are the generated GUID of each COM.
foreach (object subKey_loopVariable in t_clsidKey.GetSubKeyNames.ToList) {
subKey = subKey_loopVariable;
//For each CLSID\GUID key we get the InProcServer32 sub-key .
RegistryKey t_clsidSubKey = Registry.ClassesRoot.OpenSubKey("CLSID\\" + subKey + "\\InProcServer32");
if ((t_clsidSubKey != null)) {
//in the case InProcServer32 exist we get the default value wich contains the path of the COM file.
string t_valueName = (from value in t_clsidSubKey.GetValueNames()where string.IsNullOrEmpty(value))(0).ToString;
//Now gets the value.
string t_value = t_clsidSubKey.GetValue(t_valueName).ToString;
//And finaly if the value ends with the name of the dll (include .dll) we return it
if (t_value.EndsWith(dllName)) {
return t_value;
}
}
}
//if not exist, return nothing
return null;
}