If you know such a software, I'll purchase it with the entire company :) Many administrators around the world would buy it to clean their computers with single click.
- Uninstall all programs automatically
Not easily possible. Some programs have interactive uninstallers (dialog windows or multi-page wizards), asking you what would you like to change/remove. How would the tool go through these?
And even with clean PC installation, list of installed programs is not empty. There are some programs already preinstalled and necessary for correct function of the computer. Moreover, this list varies by manufacturer and make of computer, motherboard etc. For example, many laptops have Realtek sound driver with its custom uninstaller in list of installed programs. Launch it? (And lose the sound.) So, should really all programs be uninstalled?
- Delete all private files, including those that are locked in some way (no need for me to use Unlocker or some similar program after it is done cleaning
Almost not possible. Not only technically, but due to difficulty of classification what is private file and what not. Is custom picture of someone's user account a private file? Can it be simply deleted (as you demand) or replaced by default picture? What about registry settings (of system and applications) which keep user preferences? Some may contain configured texts, singatures, URL's, etc. Are they considered private data? And some others were created by custom drivers mentioned above. Delete them? Moreover, if computer has for example 4 user accounts, it is NOT possible to run a tool to clean registry for all 4 users at once. This is how Windows user accounts work by design. You would need to log in as each user and perform the cleanup. Is it acceptable?
- Leave other settings untouched (like computer name and users except user files of course)
Again, how do we decide which are other settings? There can be hundreds of them. For example, what about preset phone numbers and credentials for modem dialing? Almost no one uses modem dialing today, but what if someone used it and the data sit there? Actually, Windows has much more areas than most of people expect and covering them all with the tool would need enormous effort of many contributors. And who would do this on version of operating system which is officially declared 'dead'?
I think you have these options:
A. create standardized procedure to remove most significant personalization from the computer and leave the rest as it is.
B. prepare one or more disk images with clean Windows XP (and basic drivers etc.) and use them to re-image drives of your computers. This is how it is done today in most cases.
Choosing between them may depend on multiple factors, you have to find which of them works for you.