Regarding the registry file, I am not sure what it does (can you know by its content seen above?) but I know I needed to apply it since I am connected using L2TP and on windows XP. Before I applied it the dialer gave an error and did not connect. Applying that registry fix from the ISP fixed it. However I checked and IPSEC Services Service is still set to automatic (I think its the default XP setting), so the reg file might have done something else. I mentioned, my machine worked fine and there were no DHCP errors and disconnections just until a few weeks ago, and back then I had the same ISP and applied that fix (which seems to be necessary), it just started all of a sudden. I currently check with the ISP, maybe the DHCP error related to them, and not to something on my machine (and I already tried what I can on my machine). As for that psched BSOD, so far (and since I uninstalled ZA) there haven't been any of them or any similar problems.