Stream Replication archive command Access is denied question

I setup my PostgreSQL 9.0.1 Stream Replication.
Here is my config of master database address 192.168.5.4
------------------------pg_hba.conf
# IPv4 local connections:
host all all 0.0.0.0/0 trust
# IPv6 local connections:
host all all ::1/128 trust
host replication postgres 0.0.0.0/0 trust
------------------------postgresql.conf
wal_level = hot_standby
archive_mode = on
archive_command = 'copy %p D:/3SDATABACKUP/PITR/WAL/%f' # command to
use to archive a logfile segment
max_wal_senders = 5
wal_keep_segments = 32

Here is my config of standby database
------------------------postgresql.conf
hot_standby = on

------------------------recovery.conf
standby_mode = 'on'
primary_conninfo = 'host=192.168.5.4 port=5432 user=postgres'
trigger_file = 'standby.stop'
restore_command = 'copy \\192.168.5.4\pitr\wal\%f %p'

Stream Replication work well, every thing I update on master database will
exist on standby database.

But on master database log have error

2011-01-01 10:14:19 ICT LOG: archive command failed with exit code 1
2011-01-01 10:14:19 ICT DETAIL: The failed archive command was: copy
"pg_xlog\000000010000000300000056"
"D:\3SDATABACKUP\PITR\WAL\000000010000000300000056"
Access is denied.

2011-01-01 10:14:20 ICT LOG: archive command failed with exit code 1
2011-01-01 10:14:20 ICT DETAIL: The failed archive command was: copy
"pg_xlog\000000010000000300000056"
"D:\3SDATABACKUP\PITR\WAL\000000010000000300000056"
Access is denied.

2011-01-01 10:14:21 ICT LOG: archive command failed with exit code 1
2011-01-01 10:14:21 ICT DETAIL: The failed archive command was: copy
"pg_xlog\000000010000000300000056"
"D:\3SDATABACKUP\PITR\WAL\000000010000000300000056"
2011-01-01 10:14:21 ICT WARNING: transaction log file
"000000010000000300000056" could not be archived: too many failures

On computer of master database (192.168.5.4), PITR directory only have

D:/3SDATABACKUP/PITR/WAL/000000010000000300000053
D:/3SDATABACKUP/PITR/WAL/000000010000000300000053.00000020.backup
D:/3SDATABACKUP/PITR/WAL/000000010000000300000054
D:/3SDATABACKUP/PITR/WAL/000000010000000300000055
D:/3SDATABACKUP/PITR/WAL/000000010000000300000055.00000020.backup

Please Help me how to fix error on master database and will restore_command
on standby database work?

Thanks in advance.

Tuan Hoang ANh