There is all kind of changes in RHEL5 release.
In order to compile vmtools version - the following steps should be taken:
(There can be different versions of libraries - use "TAB" key in order to get the proper version)
1. GCC - if gcc isn't installed try to use add/remove components or
use the second disk of RHEL5:
rpm -i ./2/Server/gcc-4.1.1-52.el5.x86_64.rpm ./2/Server/gcc-c+-4.1.1-52.el5.x86_64.rpm ./2/Server/libstdc+-devel-4.1.1-52.el5.x86_64.rpm ./2/Server/libgomp-4.1.1-52.el5.x86_64.rpm
2. Kernel-Headers -
rpm -i ./1/Server/kernel-headers-2.6.18-8.el5.x86_64.rpm
3. And finally create link to the needed location:
ln -s /usr/src/kernels/2.6.18-8.el5-x86_64 /usr/src/linux
Regards,
Boris Mikhailovski