Did you try tg1911's suggestions, especially the freeware delete programs?
Here's another thing to try:
Download Startup Inspector which is freeware to manage your startup menu - programs that are started when Windows starts.
Startup Inspector – freeware (manages startup menu – helps you identify aps in the startup menu so you can disable unnecessary programs from running in the background when they are not needed)
Startup Monitor (a small freeware ap available on the same page to notify you and require your permission for any program to add itself to your startup menu)http://www.windowsstartup.com/download.php
Physically disconnect from the Internet and temporarily stop all programs from starting with Windows except the firewall, then reboot into safe mode and try to delete the file.
If it deletes successfully return to Startup Inspector and re-enable your av ap, anti-malware aps and any others you want running in the background.