The Problem of caching in INtranet client

The Problem of caching in INtranet client
Links for downloading files.Step wise desciption:-
1. A pdf file was removed from the directory.
2. On clicking the link in the internet explorer (IE) client, it returned "page can not be displayed"..so far so good.
3. Another file was copied to the directory and renamed with that of the deleted file.
4. On clicking the link, the previous file was displayed! why? i guess, there is caching either at server end or at client end or both.
Solution:-1. It seems caching improves performance..naturally..
2. So, what if, we just delete some charaecters from the address and re-type them and save..?sorry..does not work..!
3. ok, So, what if, we modify the link address each time a revision is uploaded?..Yes!! it works...so, each time u upload a new file..make sure to replace the filename in the htm,asp page contaning the url with new file name..dont do copy paste replace..the caching will prevent the new content from displaying..