编译得错误!!

Command line error D2016 : '/O2' and '/GZ' command-line options are incompatible
编译时加入ws2_32.lib和windows2.h之后就有了这个错误,怎么解决?
我看了一下'/O2' and '/GZ'是Projects options:中,那个可以给我讲一下这些东西有什么意思?
[244 byte] By [icelu-龙冰水] at [2008-2-12]