Cannot Log Into Administrator Account On Windows Vista

I cannot log into the Administrator account on Windows Vista. This may have been due to an accidental password change or it being compromised by a recent virus. Either way, I cannot log in and would need to do so to install malware protection software to clean out the computer. I also am not able to do this from the other accounts on the computer because they are not Administrator accounts.

Any help on this would be greatly appreciated.

 

Are you referring to a normal Windows User Account that is an Administrator account? Is it the only Administrator account on that system?
Did you recently knowingly have malware on that system, and if so what did you do about it initially?
What makes you think you entered User Accounts and somehow went through the quite detailed steps to change a User Account password by mistake?
If you really have completely lost the only Administrator User Account password on that system you might find no way of accessing the OS, such that you could carry out Administrator-only actions.
If you are the verified license key holder of the OS, it's possible MS will help you, other than that others here might be able to suggest ways you can retrieve data on the system prior to a simple clean reinstall of Windows.
Best of luck

 

http://www.howtogeek.com/96805/how-to-reset-your-windows-password-without-an-install-cd/

This CD easily works for me, but there are more ways if it doesn't...