[guardianx]

my co worker cant log onto her mac os x.2 with her acc and pw. what do i do ? what is the default username and pw for root access?

[malvolio]

There is no "default" password. You will need to boot up from an OS X installer CD, and use the password changing utility in the Installer menu.

[nsxpower]

The CD is the way to go, since there is greater then 0 chance that your co-worker didn't have root enabled in the first place.

[Jerommeke]

First try to look at every single thing: is the caps key pressed, is some key locked, maybe because loaning on it or something is in your keyboard. Type it carefully again and if that doesn't help, see above