Ever noticed that when you moved from Windows XP to Windows 7 the profile name as a .V2 appended to it? That’s because the profile format changed with Windows Vista and to avoid mistakenly loading the older profile format, Vista and upwards add a .V2 (version 2) to the profile folder name. This way a user can login to both XP and Vista/ 7 machines at the same time and the profiles won’t get mashed.
Windows 8/ 8.1 changes the format again to version 3. This time, however, they don’t change the folder name. When a Windows 7 user logs in to a Windows 8/ 8.1 machine the profile format is upgraded in-place but the folder name is not changed. Later, if they log in to a Windows 7 machine there will be trouble. Workarounds include this one from a member of the AD team or using GPOs on the computers to redirect roaming profiles to different locations (the “Set roaming profile path for all users logging onto this computer” GPO setting). More information is available in this KB article which seems to be missing.
Speaking of GPOs and roaming profiles, by default roaming profiles are configured with very minimal permissions. Only the Creator/ Owner and the Local System have full permissions to the roaming profile on the server. Administrators don’t have any permissions, including being able to see the existing permissions. There is a GPO setting which can be used to grant the Administrator group access to roaming profiles. This is a Computer policy, found under Computer Configuration > Policies > Administrative Templates > System > User Profiles and is called “Add the Administrator security group to roaming users profiles”.
Once this policy is applied to computers, when a user logs in the computer adds the Administrator group to the ACL of the roaming profile. However, this policy has a catch in that it only takes effect on roaming profiles created after the policy was deployed. If a user has a roaming profile from before the policy was deployed, the Administrator group will not be added to it. Even if the user logs in to a new machine the Administrator group will not be added (because in effect the machine is downloading the existing profile and leaving things as they are). Of course, if you delete the roaming profile of an existing user so it’s recreated afresh then the Administrator group will be added.
The only way to assign access to the Administrator group in such cases is to take ownership of the user’s roaming profile add the Administrator group to its ACLs. Best to create a PowerShell script or a batch file and automate the whole thing.