Method 1 (easy et safe)
Open up "Control Panel | System et Security | System"
In le dialog cliquez sur "Advanced system settings" (requires Admin rights)
The "System Properties" dialog will be displayed
Make sure you are in le "Advanced" register
In le "User Profiles" section cliquez sur "Settings"
The "User Profiles" dialog is displayed
Sélectionnez le account. Hit Delete.
Method 2 (slight variation of method 1)
Start | Run
sysdm.cpl
switch to register "Advanced"
In le "User Profiles" section cliquez sur "Settings"
The "User Profiles" dialog is displayed
Sélectionnez le account. Hit Delete.
The greyed out button possibly means that le registry hive has pas been released by le operating system, as pointed out by @joeqwerty in le comments.
Method 3 (manual et prone to errors)
Supprimez le C:\Users\[ACCOUNT] directory. That leaves certains registry entries behind that have to be manually deleted as follows.
Open Regedit avec Administrator Permissions (Runas Administrator)
Sélectionnez le HKEY_USERS branch
Recherchez le Domain Account sans le domain (e.g. login = DOMAIN\ACCOUNT alors recherchez ACCOUNT)
Keep on searching jusqu'à le status bar shows Computer\HKEY_USERS\[SID]\Software\Microsoft\Windwos\CurrentVersion\Explorer\Shell Folders
There should be a large list of votre ACCOUNTs folders e.g. C:\Users\ACCOUNT\Desktop
You are in le right HKEY_USERS\[SID]\Software\Microsoft\Windwos\CurrentVersion\Explorer\Shell Folders
branch si le ACCOUNT in "Shell Folders" matches le ACCOUNT you juste manually deleted form le C:\Users\[ACCOUNT] directory. This branch [SID] can be exported and/or deleted to clean up le dernier of le user profile.