VMware Workstation 7.0.1 Release Notes has a list of supported OS: http://www.vmware.com/support/ws7/doc/releasenotes_ws701.html According to that, RHEL 5.4 is listed as supported for both host and guest but CentOS 5.4 is only for guest. This is quite strange and, if it is true, that could be a serious issue. If you have VMware Workstation 7.0.x, could you tell us what you find? Did you encounter any problem when running CentOS 5.4 as a host? Thanks to nikkilocke who reported about the above release notes in the CentOS forum. Akemi