The version 4 client is definately supposed to be removed by the Endpoint client during installation, I have verified that. How many problem children do you have?
Here is what I do when dealing with "leftovers", which is the number 1 issue with all antivirus programs:
"When all else fails, discovery and removal of every anti-virus leftover!"
1) Remove all avast! versions as well as any other A/V programs from add/remove programs in control panel.
2) Download the latest version of avast! Uninstall Utility (aswclear.exe) and save it on your desktop. http://files.avast.com/files/eng/aswclear.exe
3) Start Windows in Safe Mode (F8 key before Windows splash screen on a reboot)
4) Open (execute) the uninstall utility aswclear.exe
5) Choose which version of avast! to uninstall. This process will be repeated for each avast! version. So
let's assume we had all 3 versions of avast! installed at some point. So we choose version 4.8 and proceed.
6) If you installed avast! in a different folder than the default, browse for it. (Note: Be careful! The content of any
folder you choose will be deleted!)
7) Click REMOVE, close aswclear, and open aswclear, and remove avast! 5, and repeat this process for all versions of avast, including managed client.
Restart your computer
Here is the full chimichanga "PETE SCRAPE" Do this when all else fails!
1) Add remove programs, remove avast!, restart into safe mode.
2) Use avast! removal tool, select avast! version's, and repeat for every avast version ever loaded on that system (as shown above)
3) In Local disk C:\ ProgramFiles\ , delete "avast" and "Alwil" directories if there. Look here for the other A/V vendors, that you will also have to deal with on a similar basis
4) In C:\Windows\temp, remove all.
5) Start, run, type "%temp%" and remove all.
6) Do a Windows search on all hard disks for instances of "avast" and "Alwil" and delete all.
7) Start, run, type "regedit" (Windows key + R). Under Hkey, current user, software, and remove "avast" and "Alwil", then under Hkey, local machine, software, and remove "avast" and "Alwil" (This is specific to Windows XP)
Use CCleaner to remove the rest of any avast! or other A/V for orphaned registry remnants, and restart.
9) Install avast! and reboot!
10) Usually, good luck at this point. And you can substitute other manufacturers products into this script. Remember, registry hacking is always risky, so always have a backup before you proceed. It's kinda like the acknowledgement checkbox in LSPfix, "I know what I'm doing, or, I like to reinstall my operating system"