"It is a legal requirement that pre-installed operating systems remain with a machine for the life of the machine."
Yes this is a correct statement however there seems to be some misunderstanding as to its meaning. It is quite commen in todays computer market for "OEM" products to be sold with a machine licence rather then a user licence. In essence it means it is not permissble to uninstall the software and then sell or install it on another machine, it does not mean you can not uninstall it. It also means if the pc is sold later the software must accompany the box