For all who have helped me with my problem with the undeleteable video file - thank you
FYI it has been sorted out - it turned out it was adware or spyware that had been inserted into in 'my shared folder' by the usual suspects - Ad-aware managed to do what I had tried to do multiple times to no avail - So for anyone who doesn't already use it, Lavasofts Ad-aware is a very useful resource.
The free personal version can be downloaded from here: http://www.lavasoftusa.com/software/adaware/
And for anyone who isn't familiar with my thread on the 'undeletable file' this is what happened - - I download Kazaa about once a month (the free ad-supported version) I spend a few hours downloading some new music and then I completely uninstall it and all its components (Altnet and GAIN network software).
The last time in 'My shared folder' there appeared a file named '081 sex with dog.mpeg'
This file eluded all attempts to eradicate it. It turned out to be some sort of malware and was easily taken care of by running LavaSoft's Ad-Aware.
Just a bit of a warning for anyone else who uses shareware of some sort and may experience the same problem.
I know that Adaware is not new software and many people use it - just for the ones who haven't heard of it yet or who have but have not tried it..............
Cheers again to all - and I hope this may have helped at least one person