Can't create a new thread (errno -1); if you are not out of available memory？？

Can't create a new thread (errno -1); if you are not out of available memory, you can consult the manual for a possible OS-dependent bug -

mysql-5.5.13-win32.msi

[client]
port=3306
[mysql]
default-character-set=utf8
[mysqld]
port=3306
init-file=D:\database\data\load.sql
basedir="C:/Server_Core/MySQL/"
datadir="D:/database/Data/"
character-set-server=utf8
default-storage-engine=MYISAM
max_connections=1000
query_cache_size=64M
table_cache=256
tmp_table_size=256M
thread_cache_size=128
myisam_max_sort_file_size=100G
myisam_sort_buffer_size=128M
key_buffer_size=32M
read_buffer_size=2M
read_rnd_buffer_size=2M
sort_buffer_size=8M
thread_concurrency=8
max_connect_errors = 10000000
wait_timeout = 10
skip-innodb
log-bin
binlog-ignore-db=xxx
max_heap_table_size=2048M

mysql服务器。
10G内存，八核。windows2003
出现以上错误时内存使用5.8G。
max_connections=2000 设置成2000，现在改为1000，官网说500-1000.


wait_timeout = 10 这个是不是不起作用啊。
还是需要设置什么参数？？