If your workstation is accessed by multiple users who all use the same Windows user/profile (not the norm and certainly not recommended) then you should not enable WinMount's save credentials option because anyone with access to the workstation under the same Windows user/profile will be able to authenticate as you and use FolderGrid via WinMount.
To fully disable credential saving and network drive mounting on shared workstations, start WinMount with the -p (for "Public Workstation") command line argument.
For example the following entry in the Target of a shortcut configures "public workstation" mode:
"C:\Program Files\FolderGrid\WinMount\FolderGridWinMount.exe" -p