"BlackLight is not installed in the normal sense. It is a simple executable file that is downloaded into your computer and it can be run by double-clicking on the file. There are no items in the "start"-menu or keys in the registry. "Uninstallation" of BlackLight simply means deleting the file. Location of the file is dependant on how you downloaded the file and which browser you used. If you downloaded the file with IE and chose "run", blbeta.exe is usually stored in "C:\Documents and Settings\<username>\Local Settings\Temporary Internet Files".
Yes, should have checked their site first!
