I hope to change this soon, however for now, if you have any questions or problems drop me a line at "ws, dot, processtraffic, at, starkov, dot, name".
In my experience, WinPCap installs without any difficulties on Vista 32/64 bit and Windows 7 32/64 bit. It doesn't require a reboot - you can start using ProcessTraffic straight away.
Note however that WinPCap will briefly interrupt existing connections during installation.
Simply close ProcessTraffic and run it again.
If it still shows no traffic, and you had just installed WinPCap, try rebooting your machine.
Technical: this can happen if you install WinPCap and then start ProcessTraffic immediately, before Windows had a chance to re-initialise the network interfaces. Give it another 10-20 seconds and restart ProcessTraffic, and everything should be fine.