It does not require installation, you just have to run the application to start working. Once executed, the application begins the analysis and in a matter of minutes returns the result. The time varies depending on the capacity of your hardware and how much of your hard drive is occupied.
GMER analyzes background processes, files, registry entries, and drives to recognize potential rootkits. It is also capable of exposing all currently open processes and has a kind of Windows Explorer to display any type of file on the disk.
GMER runs on Windows 2000, XP, Vista, Windows 7.
Source: Blog Antivirus

