IIS Server Banner
Now, sometime you might want to remove the IIS banner information to 'hide' your server. Though, it doesn't really help you avoid any attack as the attackers or malicious program will just try to connect to every single possible host and then try any known exploits on it. So 'hiding' is not good, you should 'protect' your IIS server instead.
Anyway, you might want to know to hide it. Ok, let's look at:
Web - banner
HTTP: Server = Microsoft-IIS/5.0
You can hide it using URLScan, try..
HOW TO: Mask IIS Version Information from Network Trace and Telnet
FTP - banner
220 Microsoft FTP Service
This one is HOT!, just released by MS. but you need to ring PSS to get the fix, try
FIX: You cannot suppress the default FTP banner for the FTP service
SMTP - banner
220 hostname.domain.com Microsoft ESMTP MAIL Service
This apply to IIS SMTP and Microsoft Exchange SMTP component, try
XCON: How to Modify the SMTP Banner
NNTP - banner
No clues yet, but you can try the nntp binary dll and hex edit it.