Boy,, this sounds like a lot of work,,, lets go backwards here a minit,,,
ok,, when you set yourself up,, you should have been asked to make an account,, at that time,, you should have also been asked what GROUP this account is to be a part of,, you should have chosen ADMINISTRATOR,,, if you did not,, well then you are probably in the USERS group..
simple way to check,, click on start >> control Panel>> administrative tools >> computer management..
Expand LOCAL USERS and GROUPs,,>click on GROUPS>> in the right panel you should see ADMINISTRATORS /BACKUP OPERATORS /POWER USERS / ...USERS
FIRST look in ADMINISTRATORS group,, if your account is not in there ,, add it,,,
IF you are unable to do this,, CLICK on USERS, and CREATE A NEW ACCOUNT that is a member of the ADMINISTRATORS group,,
if this does not work ,, try logging on as ADMINISTRATOR with no password,,
if all else fails,, there are some hacking utils, NT password utils,, etc,, if you are UNSURE as to how to use them,, DONT,,
possibly the only solution if ALL else fails is to reinstall and READ the screens during install,,
sorry ,, sounds a process ,, but it is,,