Windows password incorrect...

Hello SF. first of all, sorry if my english is not perfect.
Now here is my problem: since yesterday, i just can't open a session. When i try to log in, Windows says that the username or the passeword is not correct.
I've tried many things that i've seen on the web but still the same.
Now i just want to erase or reset password.
Or every thing can make me use my computer.
Many thanks in advance!!!

bigmck said:

There is Tutorial that should help. Try this Password Reset == You can also try a System Restore at Boot which is Option Two. You would do the System Restore to a date before you had the problem. Good Luck

Thank you Bigmck for your answer. I can't reset password with your method because i can't access to the start menu. But i'm tryng the system restore right now.
I will let you know...
Thank you again!

@Bigmck: i've tried this method but don't work for me. i can follow all steps but when it comes to the last step, i can't get Command Completed Successfully.
I've error. windows says that the synhaxe is not correct.

Hello @mitchell65: how to do that without. i can't open a session.
Still need help...
Many thanks.

I want to explain how it happens. this problem starts when i've removed a standard user.
When i restart, Windows told me directly that the password or the username is incorrect.
After that i've tried to log in but still the same. Notice that i just cant see my admin account when i switch user...
I hope these information can be usefull.
Please! if you know something to remove the password, that will be very find for me...
Thank you

Helo guys. I've finaly solved my problem. I just reinstall my windows; i know that this is not the best solution, but this situation make me stop all my Job.
Many thanks for all your advices and God bless you!!!