Clearing all data from old desktop?

I have an older Dell desktop that I run Windows 7 on. I am giving this to my sister. What would be the easiest way to clean all of my info off this? Just want her to be able to set it up the way she wants it and have nothing on it when I give it to her.

 

Is Windows 7 the original OS on that computer or was it an upgrade? If an upgrade, do you intend to leave Win 7 on it or reinstall the original OS? Are you familiar with installing an OS from scratch?

Did you normally put all your user files in the Windows 7 Documents folder? Did you use an email client (Outlook, Windows Live Mail, etc.) to download email to the hard drive? Did you accumulate favorites/bookmarks in the web browser that you'd like to save and then delete? The more info you can provide about how you used this computer, the easier for us to give advice.

 

Windows 7 was not the original OS. I am going to leave Windows 7 on there. Just want to delete all of my bookmarks, yahoo e-mail, itunes,bank info, ect. Just want this back to like it was when it was a brand new computer,with nothing on it but windows 7,and she can set it up the way she wants.

 

Surely the simple way to achieve this would be to reinstall Win 7 - only takes half an hour!

 

That's what I was thinking. Thought there might be another way. Thanks for the info

 

Might be advisable to take the format option during the reinstall. It won't remove all traces of your stuff but it would take some determination to find it