Try the manual 10g deinstall steps, environment variables and registry cleanups, etc. at Oracle&reg; Database Express Edition
The URL to the Windows Installer cleanup utility is nearly a dead link, not quite sure if the "new" utilities do the job or not. The 10g version is a bit long in the tooth, its been quite a while since patches were made unavailable for 10g from oracle.
A VM with linux is a great way to go, I'd suggest fedora, see: Fedora Project - Get Fedora: Desktops, Other Formats, Spins, Cloud Images, ARM or Secondary Arches. if you're at all familiar with the RedHat OS. A new Fedora comes out once or twice a year- but getting your feet wet on a unix-like OS going that route will be less expensive than buying a mac and there are some changes to Ubuntu making it something of a challenge to get the 11g XE linux installer to do a successful install.
Personally, I like Virtual Box, https://www.virtualbox.org/wiki/Downloads for me it works easier than one of the other VM setups that offer trial or "free" versions. The VirtBox install will pop your NIC adapters, several times, and the "certified Windows" gripes are annoying too.
Have not yet tried XE on Fedora 20 at or even 19 yet, so many other priorities needing attention. All Fedoras I've done an XE install on worked fine. One item that will help, especially if memory is tight, shrink the main OS partition by a few MiB and increase the swap partition to at least 2GiB to dodge an XE preinstall check hurdle. Installing to a 10GiB disk for the VM is enough to get XE up and running, although there won't be much room to spare for data growth.
And if you're more Windows than *nix experienced, try the KDE Live version. A Live release is about a CD-size download, easier than DVD (few options) and KDE won't be *quite* as much the OS change you'd see with a default Gnome desktop. Be sure to get the X64 version, and set the guest to X64 architecture as well.