Created A Second Administrator Account - Can't Open Control Panel

My desktop started acting strangely so I closed down programs and did a reboot which took a lot longer than normal - and later found out that my disk was full. During all of this, Windows somehow forgot where the administrator account was and created a new one that has no access. Can't open any programs, can't open Control Panel or IE. The folders for my old Administrator account are still on a second hard drive where they've always been, but Windows created a newly named Administrator account on my C: drive. I've tried the CTL ALT DEL twice trick to log in as administrator and still have the same situation. No programs work, control panel doesn't work. All give same error message, either it can't find the path or I don't have priv to access. "Windows cannot access the specified device, path, or file. You may not have the appropriate permissions to access the item."I've fixed the full C: drive issue since I can still access Windows Explorer, but can't seem to get my old Administrator account back. I can't delete the user since I can't get into Control Panel. I've started in safe mode and still have same issue.