Thanks very much for additional feedback - just the ticket!
Followed your instructions and the file in question (vtclrg41.tmp) is used
by two processess - winlogon.exe and vtserver.exe.
Winlogon not the issue as we know what that does, the relevant one is
vtserver.exe. The is a Passport Server Module from UPEK inc belobging to IBM
fingerprint authentication software. The laptop has fingerprint recognition.
It's just a pity that IBM chose to use C:\windows\temp to store the file.
Running Ashampoo Winoptimzer scans this folder and assumes, as a "temp"
folder, that all is for removal which in the case of this file, it's not.
At least my orginal question has been answered. Thanks to all those who
responded and to you for putting the final nail in the coffin. Most grateful.