As we did last week , this week we start by following up on previous topics.

Following our Gearhead column on the VMware Player , a free virtual-machine runtime utility from VMware, long-time reader Phil Daley wrote: "I can take this home and install it on my home system? Then I can create VMs at work and bring them home (assuming they fit on my 1GB flash drive) and run them? This sounds really great."

It is indeed great but it turns out, curiously, that even without VMware Desktop and with only the VMware Player you can still create custom virtual machines - see a related item on a blog run by Lorenzo Ferrara.

The first thing to do is create a hard disk image (the extension of VMware needs to be VMDK) using the program qemu-img, which you'll find in the distribution of qemu, a generic, open source processor emulator that we've discussed in a previous Gearhead column .

The key to configuring a virtual machine is the VMX file that specifies how the VM is set up. Ferrara's blog item also includes a generic VMX configuration suitable for many operating systems.

If you want to get more sophisticated there's a Windows script that we haven't tested called VMX-builder that creates VMX files, and there's a site called VM Builder that presents a Web form of virtual machine options and creates the entries for a VMX file that you copy and paste into a text file and save with a VMX extension.

The easiest setup for installing a new operating system is to create a VMX configuration with access to a real CD drive, into which you'll load the operating system's installation CD or a virtual CD drive linked to the ISO image of the installation disk.

To create the ISO image you can use any number of tools but one of the easiest is dd, a utility that is available for most operating systems. Dd comes bundled with most Linux distros and you can find a Windows version .

Once you've got a disk image and a VMX file (note that the VMX file must reference the file names of all specified disk and CD images) just fire up the VMware Player and installation will (should) begin. Voila! A new virtual machine hits the streets.

In the Gearhead column on the Player, the topic of using USB thumb drives with the VMware Player came up, the idea being to of run the Player from a thumb drive. Well, we've tried this and there are two main problems (had you read Gibbsblog , you'd be a little more up to date on this).