If you are using WIN95 in a Microsoft network, make sure that you are aren't using the original defective VREDIR network redirector. VREDIR.VXD must be dated 2/11/97 or later.
Relevant Microsoft knowledge base articles relating to this issue include: Q152186, Q165403, Q148367, and Q142803.
In addition you will need to make a registry change. See the section on opportunistic locking for further information.