Can't delete browsing history

I use windows 7 ultimate. The space below the google box extends to eternity with web titles. I have used both"safety" and "internet options" to try and delete the history without success and their presence must be slowing the machine. Can anyone please help?

 

http://www.google.com/support/websearch/bin/answer.py?hl=en&answer=465

 

Have you used, in Tools - Internet options - general. The "Browsing History", settings, "days to keep the history". ?
If you put our own figure in here (I have four days) and then select the "delete" option, under browsing history, you can heavily customise exactly what you wish to delete.

 

Their presence dosent slow down the system.
You can try Defragging the drive
Follow these steps:
Start-->Accesories-->System Tools-->Defrag
For deleting the entries Try CCleaner(Download link in my sign.)

 

My thanks to all who replied so quickly to my plight. I'm still struggling with the problem since my elderly brain takes some time to engage. However, I'm sure I'll get there with your information and one of my grandchildren's assistance re the minutiae of toolbars and drop-down menus.