There is quite a few resources around when it comes to converting Windows boxes to Virtual machines. Using VMware Converter for your conversion as a tool is pretty straightforward. It's a free tool from VMware you can Download here. But what to do if you want to convert a Linux machine which does not have GUI (graphical user interface). I'll try to help. I suppose that you have a Linux server, an workstation under XP and your infrastructure ESX.
The steps you need to do:
01.) Download Vmware Converter for linux here.
02.) Extract the converter package on your linux server: “tar xf VMware-converter-4.0.0-146302.tar.gz”
03.) Start the installation “cd vmware-converter-distrib/ && ./vmware-install.pl”
04.) You can just accept the majority of the options just make sure that you activate the remote access “Do you want to enable remote access in Converter Standalone Server? yes”
05.) Usually a linux server has an Apache installed on port 80, so good think to do is to add aditional port for https proxy : “What port do you want the HTTP proxy to use?  8080 and What port do you want the HTTPS proxy to use?  444
06.) Also you should go and allow root to login localy “/etc/ssh/sshd_config change the line PermitRootLogin yes
07.) Then you just leave your linux server and go to your Windows XP or Vista Workstation and connect to your linux server remotely via https for example “https://192.168.0.1:444”
08.) Download and install the VMware Converter client.
09.) Start the Converter Client and go to Administration > Connect to another server
10.) In the credentials window just enter the IP address followed by the port number, then the root login and password.
11.) Enter the credentials once more and choose Linux as a OS family.
12.) Then Just follow the assistant for the rest of the steps. As a destination you choose the ESX server IP address or hostname. There is nothing difficult with that…