if you have windows XP professional you can disable the ability for users to delete browsing history.
Click start and then run and enter the following in the run box
gpedit.msc
and hit enter, in the window that pops up on the left hand pane click the little plus next to each of the follow in turn
User Configuration
Administrative Templates
Windows Components
Then click on Internet Explorer and in the right hand side look down the list for "turn off "delete browing history" functionality" double click on this and then put a tick in the enable tick box at the top... clilck ok and close every thing and people will no longer be able to delete broswer history.