As far as i know these are the reg entries for doing this: I've tried the first before but not the second. How you can get this onto all machines via GPO? I'm not sure but there is a way. Try this
http://www.microsoft.com/windows2000...t/rbppaper.asp


Empty Temporary Internet Files
This will force IE to destroy temporary data stored like images. 0 will cause the destruction of these files while 1 allows it to leave everything behind!

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache]
"Persistent"="0"

Clear Internet Explorer Typed URL History

(in v.4+ of our app) This is a bit of a privacy concern on shared computers. I personally prefer not to let other people know where I've been
Delete this key you'd like to erase your typed URL history completely:
[HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\TypedURLs]