Can't rename old nsd.exe: access problem

I am trying to install the 8.5.1 FP1 on the server and I get this error message “can’t rename old nsd.exe: access problem”… the FP1 does not get installed and the only was to get rid of the error message is to press on the cancel button… i tried to search some answers in the internet but found none… please advise how to go about this error message…

Subject: Check your services.

The NSD is probably set to run as a service and is currently running.

If you switch off the NSD service you should be able to continue.

If that doesn’t work there is an MS tool called ProcessMon which will tell you what is accessing the file.

Subject: Delete files with .fp extension

This occurs because of a failed attempt to install a fixpack in the past. Simply go to your Domino program folder and delete the files with .fp extension. For example, there would be a file named nsd.exe.fp. Should be about 3 files.