Han
Thank you, no I did not use your approach, I am bit illiterate when it come to DOS.

Supersparks
Thank you, your software did not work I mentioned that in my post that I did use it without success.

dunedin
your unlocker managed to move the file but could not delete it, even after I reboot, but it managed to free most of the space, now the 5GB was reduced to 4 MB, same with file assassin no much deference.
I have gained my 5 GB back thanks to you; I can live with undeleted 4 Mb. I will hide it and forget about it.

Thank you all for the great help, great salute to Virtual DR. and the wonderful people behind it.