我没有IIS6 ISAPI_Rewrit环境测试 所以没办法一次性给你完美解决

httpd.ini 尝试放入

[ISAPI_Rewrite]
# 3600 = 1 hour
CacheClockRate 3600
RepeatLimit 32
# Protect httpd.ini and httpd.parse.errors files
# from accessing through HTTP
RewriteRule (.*)$ /index\.php\?s=$1 [I]