If you did not set up the administrator account with a password, there is no default password.  Just hit enter when it asks for a password.  If you did set it up with a password, then you need to remember it.  If you can't search on google and you will get to pages like this.

If you Google "I forgot my Administrator Password"  it will take you to a site with instructions. I don;t consider this hacking so this is the reaosn I post this.  The site has a Mice up in one corner.

jmwills, balaji,

 

thanks for the help, and I found out that I don't have an administrator password, it is blank.

 

Running msconfig, however, to try to eliminate some of the startup programs,

it still returns a message that I don't have permission to modify the startup.

Trying to log in in safe mode as the administrator, it won't let me do that either

even though there is no password.

 

Any other ideas?

 

I would try to do a few more things that you know requires elevated rights.  If those fail also, it is safe to assume you have some sort of malware running.