Things You'll Need
Instructions
Update your PSP. Make sure you are connected to the Internet and then go to the "System Settings" area on the left side of the cross-media bar. Select "Update now" to install the latest firmware. With the latest 3.7 firmware from Sony, hit triangle, choose history. Hit triangle again, then hit up, this should select "Delete All" (it's at the top of the screen). Hit X to choose this option, choose yes and you're good to go.
Restart the PSP and then start your browser. You must still be connected to the Internet. Then pull up the Internet options menu by pressing the triangle button.
Select "History" from the menu, and then press triangle again to bring up a new sub-menu, and then press the up button to highlight "select all" and then press the X button to confirm your choice.
A small window will pop up asking if you are sure you want to delete your browsing history. Select "Yes", press X, and then the deletion process will be complete.