Some clients may report an error: "The application sandbox is not accessible":
This is generally due an improper Local Application Data path in the registry or Local AppData path not accessible. You will need to verify the Local Application Data path in the registry.
Launch the registry editor (by running regedit.exe) (with user having the issue) and check the value "Local AppData" under the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders
User Shell Folders should reference:
XP Systems: %USERPROFILE%\Local Settings\Application Data
Vista/Win 7: %USERPROFILE%\AppData\Local
Shell folders should reference the expanded location of the user profile. Copy and paste the text from the registry value and see if you can browse to the local in Explorer.
A typical shell location:
XP Systems: C:\Documents and Settings\[USERNAME]\Local Settings\Application Data
Vista/Win 7: C:\Users\[USERNAME]\AppData\Local
Where [USERNAME] is the user Id. for the user.