Not being able to uninstall the Fixer is certainly not intended behavior.
First, try uninstalling normally using the add/remove function in the control panel.
If this does not work, uninstall by running unins000.exe that is located in the install path of the fixer.
If this does not remove the program, delete the install-folder.
If the Fixer keeps starting with windows, go to start -> run, ant type "msconfig" (without quotations) and press enter. Go to "autostart" and uncheck any lines referring to the DLL-files.com Fixer.
Erik at dll-files.com