I had a similar issue and simply restarting the installer (sometimes it took several restarts) allowed it to complete. Since I could work around it, I never delved into the root cause, but I suspected it was the anti-virus software running on the host. So, if you cannot get around it with restarts I would next look into turning off anti-virus, if it is running.
This is correct, the mentioned error is a result of external software (most often an antivirus) blocking executing of the OneAgent installer.
Please note that the Process Monitor from Windows Sysinternals suite is a very handy tool that will help you to precisely pinpoint the software that is interfering.
We have disabled antivirus and tried again but after that also we were facing the same issue.That server was from prod setup so prepared clone for this installation testing and this clone is not in network so possibility of interference from external software is also very low.
But appmon 7.0 agent setup is also there on that server, can it be the reason for the issue. Because we disabled appmon agent and tried but issue was still there.
If you are able to install it on this host, I would recommend you try Sysinternals Process Explorer:
Also, is it the same file each time or a different one each time?
When I had a similar issue it was different each time.
I think the temp files are created by the OneAgent installer, so I think it has to be anti-virus, automated backup or even some tmp file reaper that must be doing this. I don't see how AppMon would be a factor in the install process, but it should definitely be "uninstrumented" if not totally removed anyway as part of the OneAgent install process because there can be coexistence issues, especially on web servers.