Windows 2000 freezes at startup

Please help!!!
I was trying to clean up my parents computer for them.I knew with all these d/l I would need to restart.I disabled the password at start up.While I was searching for a file the computer shut down unexpectedly and restarted. and applying computer settings took 4 minutes and applying security settings is still working after 10 minutes.Any thoughts on what i should do.Windows2000 pro

 

You're not making sence. Restarted, downloaded, searching for a file, applying settings, ahhh take a deep breath and explain what exactly is the problem you're having?

 

Sorry,
I wanted to d/l adaware and update Windows.My sister was logged in as a administrator and the computer was on.I did not have her password so I set the other users as administrator and I changed all the passwords.( I did this because i would need to reboot).I downloaded adaware and adaware would not install automaticly so I looked for the download in the search bar/start menu.All of a sudden I get a windows is preparing to install and the computer reboots on its own.Upon loading windows it stays in prepare security policy for 20 minutes.I am able to start in safe mode ok.What should I do next.I would not be surprised if she has a virus
Thanks

 

I have tried to boot windows to last known config still have normal boot problem
I have went into device manager and looked for conflicts found a scanner error which i fixed.I then Rebooted in normal mode and still have windows is loading security policies freeze.

 

I just went into safe mode under device manager to shut off devices to see if there is a problem i shut off ethernet cards,sound,com ports cd-dvd rom drives and floppy drive.now i cannot start at all i get a 02b0 diskette drive a error.what can i do???