AlienGUIse is described as '"AlienGUIse™ Theme Manager is powered by MyColors™ technology from Stardock® and dramatically transforms the appearance of your Microsoft® Windows® operating system into a truly unique display, and features exclusive Alienware-centered skins like, Invader'. There are three alternatives to AlienGUIse for Windows. The best alternative is WindowBlinds. It's not free, so if you're looking for a free alternative, you could try UltraUXThemePatcher.
WindowBlinds is a computer program that allows users to skin the Windows graphical user interface. It has been developed by Stardock since 1998, and is the most popular component of their flagship software suite, Object Desktop.