Try run
Malwarebytes and/or
SuperAntiSpyware ASAP. After a quickscan and perhaps reboot there is reason to believe computer is cleaned up. Especially since you say current programs detected something - then those 2 should as well and then some. May be clean up better. Not that uncommon X tool cant remove infection 100%. How special tools make money
I assume it wont help to unregister dll-file, will keep coming back, over and over. Only showing you are still infected and Spy Doctor/Spybot need help

Notice the change of names, you cant remove it so easy. If you know details of infection then you dont need programs, can do it all manually after research and pin pointing but who like that?
Startup by Mike Lin is the latest and greatest in startup detection? Dont think so. Try Autoruns from Sysinternals
Autoruns for Windows There is no better and it shows a lot more and is updated. You can save output and post it here if not those 2 programs mentioned do the job. Or post Hijackthis/RSIT log. "Logon" is similar to what you posted. Unless you want confirmation computer "appear" clean there should not be reason to if removal is done properly.