Ok here's the problem. Not to give away all the details but you can probably have a good guess as to what im on about...

Problem is that there is some incriminating evidence on my family's PC and I need it gone. Tried deleting history cookies and offline content but the little "drop down box" like on the google webpage still has somje searches that will not go down well with the parents.

Can anyone help?

Have you read this article? http://www.d-a-l.com/articles/library/116.html

I am sure others will have some feedback to help as well but thats a good start.