Well, since you don't say just what you did to try to get rid of the "Tony" account, nor what happened when you tried (error messages, system behavior, etc.), I'll just take a guess. If you told the system to set up the account as "Private" then access to the directory structures under the account would be limited to the "Tony" account only (assuming this is an NTFS installation). You can fix that by taking ownership of the structures. How you do that would depend upon which Windows XP (Home Edition or Pro) you are running. But booting into Safe Mode and logging in as the administrator then navigating to the account location in Windows Explorer and using the sharing and security dialogs would work for either version of the OS.
BTW, I think it makes sense to keep two admin level accounts on a machine, even if you only use one of them. If I were going to constantly use an admin account, I'd make it the one I created during setup, reserving the built-in admin account for emergencies and certain types of maintenance. If you only have the one admin account and something happens to bork it (like a software or driver installation gone berserk), it's reinstallation time for the whole system.
- prosaic