software updating problem

most of the time when I update the software, the folder created is

application_date_time and the old application remains with one single file

and sometimes the update is perfect

what am I missing?

Usually, folders with date/hour in their names are the most recent one and would replace the original folder but:
It's always due to the system which holds the folder (or a file inside it) and Liberkey can't replace it with the new one (with date/hour inside its name).
This could be because the software were still running at update time.
This could be because a dll were (sadly) registered in the system and not properly cleaned at software closure.
this could be because an antivirus analysis is running (it reads and holds the folder or a file inside it) during update time.
This could be because....

are you suggesting that AV should be turn off during updating?

No I don't !
You have different solution available:
- update your virus database
- change your antivirus for less "sensitive" one (I never have any issue with an up to date Nod32, kaspersky or bitdefender but I had lots of issues with avira, avast, AVG, norton, panda, etc)

I am using MS Security Essentials

I switched it off temporary to install an update and so far it works

Just a quick note: I find on my systems, that the files with the dates in the file names appear to be the older versions and the file without a date are the latest updates. I also am using MS Security Essentials (ver. 2 beta) and other than one program that pops up a false positive as a virus, I have not (knowingly) had a problem with it.