Although phamine has already released a bandwidth monitoring program Du Meter 3.07 over in the Switchless Installer Addon Packs section, I personally prefer the most excellent freeware program NetMeter which I have been using faithfully for 2 years now without a single hitch.
SIZE: 317 KB
Description: Windows network bandwidth monitoring program
Op System: Windows 2000, XP & 2003 (x86 only)
Installs to: "%programfiles%\Network\NetMeter"
Uninstaller: Removes program files, shortcuts, personal settings and 2nd prompt to remove traffic logs
NetMeter is a small, customizable network bandwidth monitoring program for Windows 95/98/98SE/ME/NT4/2000/XP. NetMeter is and will always stay freeware.
The program has been tested extensively on Windows 2000 and XP, but it should work just as well on all other Win32 operating systems.
The best things in life are free....
[Edit 2006/03/08] Recoded ALL Mrs Peel Addon Packs for platform and licencing compliance.
[Edit 2007/06/20] Updated to new version v1.1.0b.
[Edit 2007/06/24] Updated to new stable version v1.1.2
[Edit 2007/06/24] Rebuilt with uninstaller
[Edit 2007/08/14] Updated to new stable version v1.1.3
[Edit 2007/08/15] Added delreg entries to cleanup autostart with windows
[Edit 2007/10/08] Rebuilt with 2-stage uninstaller with prompt to preserve accumulated traffic logs