clean up files???

i am selling my laptop in the trade and exchange....i used it for work and personal stuff.
therefore i want to clean up any history etc i have on there.
regarding internet....i thought i had deleted all but a friend said that there are "logs" and other places that i have probably missed??
i have been into internet options...and done the following;
-delete files under the general tab
-delete cookies under the general tab
-clear history under general tab
-clear forms and passwords under content tab

i thought this would get rid of all as if it was a cleanly loaded computer??
but for example...i watched a movie trailer for star wars the other day....which took a while to get through windows media player....then after i had done all the steps above...clearing history etc....the next day when i went to watch the trailer again...it played straight away as if it was still somewhere on my hard drive???

please...can someone give me a list of all folders etc i need to delete or clear?

any help would be greatly appreciated

thanks

 

Mabey you should consider reformatting.

 

Just to make sure I (personally) would reformat.

 

hey,

thanks a lot for your help...i really do appreciate it.
i will try this CCleaner program...as i only just reformatted a few weeks ago and don't really want to go through that whole process again since i will use the laptop until it sells anyway.

thanks again.