When you uninstall Logical Forex, it is completely removed from your system, leaving no traces on your drive or reqistry.
How you install depends on your version of Microsoft Windows, and which version of the Logical Forex Installer you used.
If you have installed "recently", then check your Windows "Start" Menu under "Logical Forex", and in the "View More" menu choice, you will find "Uninstall Logical Forex".
Alternatively, you may use your Windows Control Panel tool "Add/Remove Programs" (in XP) or "Programs And Features" on newer versions of Microsoft Windows such as Vista and Windows 7.
