Original sentence: Different companies offer varying degrees of customization, some almost as much as building it oneself.These PCs are almost always more expensive than building ones own.While many "hardcore" gamers build their gaming PCs themselves, people with little or no experience in computer hardware prefer to go with prebuilt or custom-built gaming PCs
Edited sentence: ) Most gamers do not use Mac OSs, as most games are not compatible with Macs.Among the most high profile of these companies include Falcon Northwest, VoodooPC, Velocity Micro, and Alienware.Besides the actual Gaming Software, Gaming PCs usually do not have any software other than the default software bundled with the PC (an exception might be an office suite like Microsoft Office).Despite this, support is generally low, as the non-compatible games run under virtualisation software have slight technical problems and/or Graphics problems.Different companies offer varying degrees of customization and options.However, there are a few Mac/Windows games, and some game manufacturers release Mac versions of games.However, with the advent of DirectX 10, some PCs are equipped with Vista (the solution might be one computer for primary gamign running Windows XP and a secondary computer running Windows Vista, for DirectX 10 gaming.In the past 20 years, "boutique" manufaturers have come on the scene to take advantage of the large market for fast, reliable, and well built gaming computers.Larger companies have also started their own lines and even aquired some of these smaller gaming specific companies in an effort to capitalize on this market both for finacial gain and as a "sounding board" resulting from gamers being at the forfront of new technology that eventually makes it's way into mainstream computers.Most gaming PCs are currently equipped with Windows XP, as it is faster and supports older technologies more reliably than Windows Vista.These PCs are almost always more expensive than building one's own.While many "hardcore" gamers build their gaming PCs themselves, people with less experience or even experienced computer builders  may opt for prebuilt or custom-built gaming PCs since one does not have to deal with hardware issues and other such items that arise when doing it yourself