This post covers how to correctly disable Offline Files in Windows Vista. I recently experienced undesirable behavior with a file share only when the file server was accessed from their Windows Vista machines. The supported way to disable Offline Files is to use the Offline Files GUI in Control Panel, Group Policy, or WMIC.
To enable/disable Offline Files via Group Policy: This is a Computer Configuration setting under Administrative Templates\Network\Offline Files named "Allow of Disallow use of the Offline Files feature". Once the GPO applies, a reboot is required for the setting to take effect.
To enable/disable Offline Files via WMIC: We use the Enable method of Win32_OfflineFilesCache to enable or disable offline files. Simply pass the Enable method a Boolean value.
A reboot is required for the new setting to take effect.
Source:→ TechNet Blog