as soon as mirc finishes downlading, when it reaches 100%, it freezes. just locks up. i wait a minute then it says "program not responing"

Please see this thread where somebody reported similar problem.

well it turns out that even though it froze, it finished downloading, i searched for it under my computer and the folder turned up, thnx anyway

Just FYI, any time a program shows "program not responding" in windows, it just means that it's not allowing any interupts to it's process. Often this happens to mIRC because of a script running, and if this is the case you can press Ctrl+Break to halt it's operation. If it's in the middle of a file copy, this might not be a great idea. Just let it go on until mIRC responds again and all should be OK with mIRC and your file. Just reconnect to your network and resume chatting.

Oh, and mIRC is not meant to be a file-trading program.

if you have norton anti virus 2004 then thats what is causing the problem.

Norton freezes the program that downloads something until the virus scan is complete. If the file is very large or contains a large amount of smaller files, norton can take anything up to 10 minutes to scan.

disabling auto protect 30 seconds before the download is due to finish and then re-enabling it afterwards will stop norton doing this (but remember to do a manual scan of the file afterwards)

If you havn't got norton anti virus 2004, then i'm afraid i can't help you.