password trouble

I have a computer running windows xp , I left my computer on the other day and there was a lightning storm! The power went out, so I just left the computer off! Now I go to log on a administrator , I can't tells me the password is wrong! So I try my own log on, it tells me my password as that user is no good! I am now log on as a guest! I can not get into my user or administrator! I am positive of my passwords, so is there a reason for this and is there a solution?

 

If you get your answer, I may get mine too. My fiance's computer will not boot at all to windows. The hard drive is sata and the sata drivers seem to be missing and I assume the mbr is corrupt. When I go into recovery, it wants an administrator password but we never set any passwords on this computer not even one for his master account. The computer was never password protected at all but now there is one for the administrator account and I cannot do repair without it. Unless there is a way other than a forty dollar program out there I found to remove admin passwords, I don't know what to do. Anybody know what to do to fix this? How does a mystery password just show up?

 

There are ways, however most "general" help forums have rules about helping to circumvent any passwords. Any member who posts such information can be permanently banned from the site.

 

It really is too bad this is the case. That means reprogramming the OS is the only fix.:cry