Hi, are you using windows xp
windows 8 its a toshiba satelite850
Do you have any other accounts setup on the machine?
Can you also advise where you purchased it from, eg PC World etc?
Argos and no
When you created an account did you set a security question?
If you havent set a security question, depending on if your machine has the lasted windows patches this may work.
The video shows you step by step, it takes about 5 minutes, and you need the windows CD which came with your machine.
There is also another option of using a third party piece of software which is free, should the above not work and this is defined on this video. https://www.youtube.com/watch?v=HoYv1H6-E98
Try both of these, and let me know how you get on and if you have any specific questions, however hope one of these will get you back in. Once back in, I would suggest you setup the forgotten password feature within Windows, which saves all this grief.