This has been painful. My internet connection on the Guest Windows side stopped working. I was using Parallels 4. I reinstalled Tools, to no avail. I rebooted tons of times, both Mac and VM. I even went back to a Snap Shot and it worked at first. Then after VM reboot, the internet stopped. I assumed it was product bug so I went so far as updating to Parallels Desktop 5. Yeah same problem remained! I have read all the threads and tried what I think is everything: * Attempted to uninstall the Network Device on Guest OS - the VM does not like this. It typically fails. * Re-created a network adaptor from the Parallels Configuration. Does nothing. * Hard coded and went with DHCP on Mac Network side for the Parallels Guest Ethernet Adaptor #0. * I even SAFE-MODED it and remove all network devices. When reboot it works until next boot. By not working I mean the Network device shows the Parallel Ethernet Adaptor. The networking control panel shows the "enabled" adaptor connector to a local area connection. The status is connected. But zero packets are move in or out. And if you click repair - it fails immediately saying no TCP/IP connection. >ipconfig /all returns nothing. I would not be surprised if there is something on Mac side I need to tweak, but I don't know where to start. I am running 10.5.8 with Parallels 5 for Windows XP.