Open the registry editor and find your installation under:
\\\Registry\HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\
Admin installations reside here:
\\\Registry\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\
\\\Registry\HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Uninstall\
Remove the entry from the registry and delete the installed files using the explorer.