was tryin to boot up my desktop PC (windows xp pro) after not using it for a few months, and i have forgotten the password! cannot log into administrator or my regular account! have tried a couple "backdoor" type fixes without much luck. any help would be appreciated, thanks bunches!

Without the password the outlook is grim. This site and members will not help circumvent any O/S security measures. We do not provide "back door" solutions. You will have to try to remember the passwords a bit harder, or reload XP.