Cisco Router 2651XM – problem upgrading

Hello,

I’ve been trying to upgrade our Cisco Router 2651XM with a newer IOS version but failed all the time. I’ve already downloaded the new version I need.

I have also installed the Cisco Network Assistant to upgrade the device but didn’t work…it keeps showing upgrade failed.

I’ve used tftp server but didn’t work either(tried 2 tftp server software recommended by several folks). I used the tftp server to upgrade my firewall and worked but won’t work with the router.

I’ve also consoled in to the router and used ROMmon to upgrade directly but didn’t either. I’m not sure what I’m doing wrong. Any information regarding this matter is appreciated. Thanks in advance!

-Philip