I'm kind of confused about what you have.
If you created a virtual computer on one netbook, and copied the VM files directly to a DVD, the files are now read-only and that can cause problems. Anything you copy to CDR or DVD+R becomes read-only.
In order to avoid unwanted read-only attributes, you can either use a
***USB flash drive*** instead of a DVD+R, or use an archive program (like Winzip or 7-zip or WinRAR) to compress the files before copying the zipped file to the DVD+R. The compressed file will be read-only, but once you unzip it the original files will have retained their original attributes.
I have not used VMware Player 3. I've used an earlier version in the past, but that was more limited than the current version and you pretty much had to go into the files and figure out how to edit them in order to change things around. I'm not sure how the current version works as far as deleting virtual machines, but it's probably easier.
However if you are trying to delete a VM that was copied from a DVD, and is read-only, that may be creating a problem. If you can locate the files, you can remove the read-only attribute by right-clicking the file, choosing Properties, and unchecking the box for the read-only attribute.