Problem with Administrator log in

Hello All,

I am new MS Vista user. After installing Vista on my laptop I removed Admin rights of my user to have more security. But then I am not able to log in as Administrator at all. I tried -
1. running command prompt as administrator by right clicking
2. switching user from command prompt using RUNAS command
3. enabling admin account by net user administrator /active:yes resulted access denied
4. installing software and typed admin password when prompted for password
5. turn UAC on or off

All above actions are not working. I am sure that password is correct.
Please help me how can I log in as admin on my machine.

Thanks,

Resolved..

I restarted the computer in safe mode.. and logged in as Administrator..
then added my normal user in admin group