I've used the FiOS Speed Optimizer tool successfully on two computers in my home (XP home and Win2k) but on two other machines (XP home and XP Pro), it fails with the message:
Optimization of your current system settings failed.
In all of the cases, I've run as the Administrator/Owner. I've tried both IE and Firefox on both machines and also tried the direct link at http://verizon.net/optimizesettings/. On both machines, I've allowed the ActiveX control to do it's thing. On my XP Pro machine, I thought I'd look through the registry for things like Tcp1323Opts and GlobalMaxTcpWindowSize - both keys that had been modified on my Win2k machine. However, I couldn't find anything in the registry for Tcp window size. I'd rather have the Verizon script make the appropriate modifications, but it won't work. Any ideas?