Very simple answer...
Save the page on your hard drive. File, save as ... (In IE anyways ...)
Give it a location, and you will be given the html page, and a folder containing relevent graphics, etc. for the page, that you can bring up locally on your hard drive.
You may then delete TIF with impunity. <img src="smile.gif" border="0">
Of course if you are deleting temp internet files from the control panel, you are given an option after selecting delete ON whether to delete offline content or not in the first place, not selecting to delete all offline content should result in removing temp internet files without affecting the ones you choose for offline viewing.
[ 18 January 2002: Message edited by: RW-1 ]</p>