Enable Aero
While one may try the suggested manual ways, Aero Enabler can enable Aero for you and additionally disable the Hardware Check if required, in a click! This tool changes some registry settings and there might be problems if your computer does not meet Aero’s system requirements, so best to create a system restore point first! Its publisher has also released two other tools Protect Me! Beta 1 & Tweak Me! Beta 3 which you may want to check out. Download Page. Please note that I haven’t tried this tool.