This is an example of installing MinGW and required packages for compiling the OSSEC Windows Agent on CentOS 7.
# yum install epel-release
# yum makecache fast
# yum install mingw32-gcc.x86_64
# yum install mingw32-nsis.x86_64
# cd /home/user/ossec-hids-master/src
# make clean
# make TARGET=winagent
# cd win32