I have windows XP but someone gained access to my computer and created a new password (I don't know who), possibly a hacker. Now I can only login as guest and not admin. I've used lopht crack 2.5 but it doesn't work, I tried lopht crack 5 also but you need to be logged in as admin to install it. I tried to bypass the syskey .exe file, but still no hope. What can I do to recover my password and login as admin again. Could I replace my sam file with another sam file from a friends computer whose password I know?

use File transfer Wizard from your friend's computer and transfer the same file onto your computer as a back up using null modem serial cable the one with 9 pins...if your friend's PC and yours are not connected via network, that is.

What if I just took my friends SAM file and put it on a disk and just copy it to my computer and replace my sam file? would that work?

sure, that will work too