Error 766 on Windows 7 when try to connect to L2TP/IPSec with cert

Hello,

I done working vpn based on this manual, but I want use certs instead of text password string.

From this manual I prepare certs:

[admin@MikroTik] /certificate> print
Flags: K - private-key, D - dsa, L - crl, C - smart-card-key, A - authority, 
I - issued, R - revoked, E - expired, T - trusted 
 #          NAME    CO.. SUBJECT-ALT-NAME                                  FI..
 0 K L A  T myCa    myCa                                                   50..
 1 K   A  T server  se..                                                   2e..
 2 K   A    client1 cl..                                                   1d..
 3 K   A    client2 cl..                                                   a6..

Export these certs and copy its to Win7 workstation and install cert_export_client1.crt and cert_export_myCa.crt.

When I try to connect, I receive error 766 - cert not found.

Please give me advise how to use certs for vpn connection!