Index: wintrust_main.c
===================================================================
--- wintrust_main.c	(revision 23867)
+++ wintrust_main.c	(working copy)
@@ -83,7 +83,26 @@
  */
 LONG WINAPI WinVerifyTrust( HWND hwnd, GUID *ActionID, LPVOID ActionData )
 {
+    static const GUID gen_verify_v2 = WINTRUST_ACTION_GENERIC_VERIFY_V2;
+
     FIXME("%p %s %p\n", hwnd, debugstr_guid(ActionID), ActionData);
+
+    /* Trust providers can be found at:
+     * HKLM\SOFTWARE\Microsoft\Cryptography\Providers\Trust\CertCheck\
+     *
+     * Process Explorer expects a correct implementation, so we 
+     * return TRUST_E_PROVIDER_UNKNOWN.
+     *
+     * Girotel needs ERROR_SUCCESS.
+     *
+     * For now return TRUST_E_PROVIDER_UNKNOWN only when 
+     * ActionID = WINTRUST_ACTION_GENERIC_VERIFY_V2.
+     *
+     */
+
+    if (IsEqualCLSID(ActionID, &gen_verify_v2))
+        return TRUST_E_PROVIDER_UNKNOWN;
+
     return ERROR_SUCCESS;
 }