I've been unable to get at least one program (vmware-tools) to build correctly on my VMWare box - unable to build "vmhgs" module, and it complains : "The kernel defined by this directory of header files does not match the address space of the running kernel." uname -r --> 2.6.15-1.2054_FC5 In /usr/src/ linux is a symbolic link to: kernels/2.6.15-1.2054_FC5-i686 The FC5 release notes mention how to install kernel sources, many of the steps in that document do not work (or no such file or directory exists - for example - there is nothing called ....src.rpm in the DVD, yumdownloader fails when I give it --source kernel, etc), so I followed the gist of the instructions only: I have the DVD .iso image, and in it I found: Fedora/RPMS/kernel-devel-2.6.15-1.2054_FC5.i686.rpm That is what I installed, since it matched my "uname -r". But looks like that is not right, or that the "vmware-tools" package is wrong in the way it tries to compile its "vmhgs" module. Anyone got the kernel sources working in FC5, or if anyone can say if the -devel- package I used above is fine, and best of all - if you have vmhgs module compiled on your FC5 platform, how did you do it???