Oh, I forgot :
After installing URLsnooper but not WinPcap, as soon as I launch URLs, I get a message telling about WPCAP.DLL not found.
No severe crash of the machine.
Then I install WinPcap and launch URLSnooper : Black screen and the machine autoboots, making a scandisk.
Found this at WinPcap's :
Q-14: On which OS can I run WinPcap?
A: WinPcap can run on all the main Win32 operating systems: Windows 95, 98, ME, NT4, 2000, XP, 2003. If you have Windows XP/2003, you need WinPcap version 2.3 or higher. Note: the old family of Windows operating systems, i.e. Windows 95, Windows 98 and Windows ME, is no more supported by the WinPcap team, so if you use them you are on your own.
Regarding Windows Vista (also known as "Longhorn"), WinPcap 3.1 should work, but with limited functionality: PPP is not supported (at least on Vista BETA1), and IPv6 addresses are not listed. We plan to address these issues soon after the release of WinPcap 3.1.
64-bit operating systems are not supported yet.