VMWare Server is pretty easy to install if you're not scared of using shell commands, but there are some steps beyond the basic install that you need to go through to make sure the clock on your guest operating system is correct.
Read it here
In my early trials of VMWare I tried to run ntp inside my virtual machines and had all sorts of trouble with the guest OS's interfering with the host OS's clock and vice-versa. After a bit of Googling around I found this document about time keeping in virtual machines on the VMWare site. It's really required reading if you want to setup your VM's properly.