in my Avast C:\Program Files\AVAST Software\Avast - I have many, many tmp files but cannot delete as it says I do not have permission even though I am an admin.
below are some examples
Aav44c2.tmp
Aav4521c.tmp
AavA09E.tmp
Are you saying the files are directly in the Avast installation folder? If so, it’s most likely a new version ready to be applied during the next reboot. (If you remove them in that case, I would guess Avast will stop working after reboot - and hopefully just Avast).
Or are you saying the tmp files stay there across reboots?
@ Igor
Whilst I don’t appear to have lots of tmp files I would query the Avast Housekeeping the Avast\Setup folder is chock-a-block with folders and files with names like SHA/MD5 numbers. For the most part these folders appear empty or have another sub-folder/s most of which are also empty.
So perhaps these tmp files of the OP could be remnants of housekeeping not being carried out.
They Go back for some considerable time (oldest 22/5/2017 23:24) and right up until today (16/2/2018 13:29).
Image extracts from top and bottom of the range.