Verify that the TFTP server is open on your PC. Also, make sure the file is in the root directory. From the TFTP application software menu bar, choose View > Options.
Try to eliminate extraneous networking complexities between the router and the TFTP server, such as hubs and switches, or reduce the hop count between the router and server. This may involve moving the TFTP server or setting up a new server on a network segment topologically closer to the router or on the same LAN segment as the router.
If these actions fail to resolve the problem, try using different TFTP server software.
Free TFTP server software is available for download on the Internet.
For more information refer to these documents:
- The Changing the TFTP Timeout section of Serving Files with the TFTP Service
- Common Problems in Installing Images Using TFTP or an RCP Server TFTP Server Selection and Use